The Brief Multidimensional Assessment Scale (BMAS): A Broad Measure of Patient Well-Being.

OBJECTIVE: This article discusses the development and initial clinimetric and psychometric properties of the Brief Multidimensional Assessment Scale (BMAS). The BMAS is an ultrabrief multidimensional measure of global patient well-being that can be used at every clinic visit to assess several facets of patients' perception of themselves, regardless of their diagnosis, at a moment in time and over the course of treatment. METHODS: Data were collected from 499 adults in the community as well as from psychiatric and medical inpatient and outpatient settings. Participants completed questionnaires as part of their standard care at inpatient and outpatient medical and psychiatric settings or completed them online (community sample). RESULTS: Results indicate that the BMAS measures four discrete dimensions: the ability to get things done, emotional support in important relationships, quality of life, and sense of purpose in life. The scale demonstrates concurrent validity with other measures and discriminates between nonclinical participants and participants from most clinical contexts. CONCLUSIONS: The BMAS demonstrates promising initial psychometric properties. It offers clinicians a multidimensional measure of their patients' well-being, regardless of diagnosis, that can be used to monitor well-being at each routine appointment and over time.

Feasibility Studies of Charge Exchange Measurements in pp Collisions at the LHC.

(1) Pions produced in the development of extended atmospheric cosmic ray air showers subsequently decay to muons. The measured yield of those muons is generally underestimated by current phenomenological models and event generators optimized for cosmic ray physics. The importance of those disagreements motivates the feasibility studies for testing these models at the Large Hadron Collider (LHC) energies, at the highest center-of-mass energies achievable in a laboratory. The interaction of a nucleus and a virtual pion created in a charge exchange reaction at the LHC is a similar process to those contributing to the development of air showers in case of cosmic rays. The crucial problem of such an analysis is the selection of charge exchange events with the highest possible efficiency and high purity from proton-proton collisions at the LHC. (2) For this we consider distributions of various measurable quantities given by event generators commonly used in cosmic ray physics. (3) We examine the expected distributions of energy deposited in different calorimeters of an LHC experiment. We consider the geometrical acceptance and energy resolution of the detectors at the Compact Muon Solenoid (CMS) experiment, as an example. We determine a working point cut from the various options for event selection, and compare signal and background predictions using different models for a representative simple observable, such as average transverse momentum or charge particle yield. (4) A set of event selection cuts along these considerations is proposed, with the aim of achieving optimal efficiency and purity.

The Brief Assessment of Family Functioning Scale (BAFFS): a three-item version of the General Functioning Scale of the Family Assessment Device.

The purpose of the present study is to compare results from the 12-item General Functioning Scale (GF-FAD) of the Family Assessment Device (FAD) to a three-item version, the Brief Assessment of Family Functioning Scale (BAFFS), designed to be used when brevity is especially important. We used principal components analysis of the GF-FAD, followed by multiple sample confirmatory factor analyses to test the robustness of the BAFFS in different samples. The BAFFS correlated highly with the GF-FAD, and demonstrated good concurrent validity with another measure of global marital functioning, the Dyadic Adjustment Scale-4 in a help-seeking sample. Like the 12-item version, the BAFFS moderately correlated with an objective, interview-based rating of family functioning, the McMaster Clinical Rating Scale. The BAFFS appears to serve as a good proxy for the GF-FAD when an ultra-brief family assessment measure is needed.

Simple Modifications of the SCAN Meta-Generalized Gradient Approximation Functional.

We analyzed various possibilities to improve upon the SCAN meta-generalized gradient approximation density functional obeying all known properties of the exact functional that can be satisfied at this level of approximation. We examined the necessity of locally satisfying a strongly tightened lower bound for the exchange energy density in single-orbital regions, the nature of the error cancellation between the exchange and correlation parts in two-electron regions, and the effect of the fourth-order term in the gradient expansion of the correlation energy density. We have concluded that the functional can be modified to separately reproduce the exchange and correlation energies of the helium atom by locally releasing the strongly tightened lower bound for the exchange energy density in single-orbital regions, but this leads to an unbalanced improvement in the single-orbital electron densities. Therefore, we decided to keep the FX ≤ 1.174 exact condition for any single-orbital density, where FX is the exchange enhancement factor. However, we observed a general improvement in the single-orbital electron densities by revising the correlation functional form to follow the second-order gradient expansion in a wider range. Our new revSCAN functional provides more-accurate atomization energies for the systems with multireference character, compared to the SCAN functional. The nonlocal VV10 dispersion-corrected revSCAN functional yields more-accurate noncovalent interaction energies than the VV10-corrected SCAN functional. Furthermore, its global hybrid version with 25% of exact exchange, called revSCAN0, generally performs better than the similar SCAN0 for reaction barrier heights. Here, we also analyzed the possibility of the construction of a local hybrid from the SCAN exchange and a specific locally bounded nonconventional exact exchange energy density. We predict compatibility problems since this nonconventional exact exchange energy density does not really obey the strongly tightened lower bound for the exchange energy density in single-orbital regions.

Electron Density Errors and Density-Driven Exchange-Correlation Energy Errors in Approximate Density Functional Calculations.

Since its formal introduction, density functional theory has achieved many successes in the fields of molecular and solid-state chemistry. According to its central theorems, the ground state of a many-electron system is fully described by its electron density, and the exact functional minimizes the energy at the exact electron density. For many years of density functional development, it was assumed that the improvements in the energy are accompanied by the improvements in the density, and the approximations approach the exact functional. In a recent analysis ( Medvedev et al. Science 2017 , 355 , 49 - 52 .), it has been pointed out for 14 first row (Be-Ne) atoms and cations with 2, 4, or 10 electrons that the nowadays popular flexible but physically less rigorous approximate density functionals may provide large errors in the calculated electron densities despite the accurate energies. Although far-reaching conclusions have been drawn in this work, the methodology used by the authors may need improvements. Most importantly, their benchmark set was biased toward small atomic cations with compressed, high electron densities. In our paper, we construct a molecular test set with chemically relevant densities and analyze the performance of several density functional approximations including the less-investigated double hybrids. We apply an intensive error measure for the density, its gradient, and its Laplacian and examine how the errors in the density propagate into the semilocal exchange-correlation energy. While we have confirmed the broad conclusions of Medvedev et al., our different way of analyzing the data has led to conclusions that differ in detail. Finally, seeking for a rationale behind the global hybrid or double hybrid methods from the density's point of view, we also analyze the role of the exact exchange and second-order perturbative correlation mixing in PBE-based global hybrid and double hybrid functional forms.

Construction of a Spin-Component Scaled Dual-Hybrid Random Phase Approximation.

Recently, we have constructed a dual-hybrid direct random phase approximation method, called dRPA75, and demonstrated its good performance on reaction energies, barrier heights, and noncovalent interactions of main-group elements. However, this method has also shown significant but quite systematic errors in the computed atomization energies. In this paper, we suggest a constrained spin-component scaling formalism for the dRPA75 method (SCS-dRPA75) in order to overcome the large error in the computed atomization energies, preserving the good performance of this method on spin-unpolarized systems at the same time. The SCS-dRPA75 method with the aug-cc-pVTZ basis set results in an average error lower than 1.5 kcal mol-1 for the entire n-homodesmotic hierarchy of hydrocarbon reactions (RC0-RC5 test sets). The overall performance of this method is better than the related direct random phase approximation-based double-hybrid PWRB95 method on open-shell systems of main-group elements (from the GMTKN30 database) and comparable to the best O(N4)-scaling opposite-spin second-order perturbation theory-based double-hybrid methods like PWPB95-D3 and to the O(N5)-scaling RPAX2@PBEx method, which also includes exchange interactions. Furthermore, it gives well-balanced performance on many types of barrier heights similarly to the best O(N5)-scaling second-order perturbation theory-based or spin-component scaled second-order perturbation theory-based double-hybrid methods such as XYG3 or DSD-PBEhB95. Finally, we show that the SCS-dRPA75 method has reduced self-interaction and delocalization errors compared to the parent dRPA75 method and a slightly smaller static correlation error than the related PWRB95 method.

Application of a Dual-Hybrid Direct Random Phase Approximation to Water Clusters.

In water clusters, there is a delicate balance of van der Waals interactions and hydrogen bonds. Although semilocal and nonlocal density functional approximations have been recently routinely applied to water in various phases, the accurate description of hydrogen bonds remains a challenge. The most popular density functional approaches fail to predict the correct ordering of the energies of water clusters. To illustrate the required accuracy, the CCSD(T) complete basis set extrapolated dissociation energy difference between the two lowest energy hexamer structures is 0.06 kcal mol(-1) per monomer. In this work, we assessed interaction energies in neutral and ionic water clusters with various density functionals with or without van der Waals correction. Generally, van der Waals approximations play a significant role in clusters with increasing size, while hybrid functionals improve the description of hydrogen bonds. Despite these general trends, none of the tested density functional approximations with or without van der Waals correction and exact exchange mixing can lead to a uniform performance for neutral and ionic water clusters. The recently constructed dual-hybrid dRPA75 approximation is a successful combination of exact and semilocal exchange, and nonlocal correlation in its energy, while utilizing a high fraction of exact exchange. We have shown that the dRPA75 method has a systematic error, which can be efficiently compensated for by the aug-cc-pVTZ basis set for small- and medium-sized water clusters.

Accurate Diels-Alder reaction energies from efficient density functional calculations.

We assess the performance of the semilocal PBE functional; its global hybrid variants; the highly parametrized empirical M06-2X and M08-SO; the range separated rCAM-B3LYP and MCY3; the atom-pairwise or nonlocal dispersion corrected semilocal PBE and TPSS; the dispersion corrected range-separated ωB97X-D; the dispersion corrected double hybrids such as PWPB95-D3; the direct random phase approximation, dRPA, with Hartree-Fock, Perdew-Burke-Ernzerhof, and Perdew-Burke-Ernzerhof hybrid reference orbitals and the RPAX2 method based on a Perdew-Burke-Ernzerhof exchange reference orbitals for the Diels-Alder, DARC; and self-interaction error sensitive, SIE11, reaction energy test sets with large, augmented correlation consistent valence basis sets. The dRPA energies for the DARC test set are extrapolated to the complete basis set limit. CCSD(T)/CBS energies were used as a reference. The standard global hybrid functionals show general improvements over the typical endothermic energy error of semilocal functionals, but despite the increased accuracy the precision of the methods increases only slightly, and thus all reaction energies are simply shifted into the exothermic direction. Dispersion corrections give mixed results for the DARC test set. Vydrov-Van Voorhis 10 correction to the reaction energies gives superior quality results compared to the too-small D3 correction. Functionals parametrized for energies of noncovalent interactions like M08-SO give reasonable results without any dispersion correction. The dRPA method that seamlessly and theoretically correctly includes noncovalent interaction energies gives excellent results with properly chosen reference orbitals. As the results for the SIE11 test set and H2(+) dissociation show that the dRPA methods suffer from delocalization error, good reaction energies for the DARC test set from a given method do not prove that the method is free from delocalization error. The RPAX2 method shows good performance for the DARC, the SIE11 test sets, and for the H2(+) and H2 potential energy curves showing no one-electron self-interaction error and reduced static correlation errors at the same time. We also suggest simplified DARC6 and SIE9 test sets for future benchmarking.

Accurate, precise, and efficient theoretical methods to calculate anion-π interaction energies in model structures.

A correct description of the anion-π interaction is essential for the design of selective anion receptors and channels and important for advances in the field of supramolecular chemistry. However, it is challenging to do accurate, precise, and efficient calculations of this interaction, which are lacking in the literature. In this article, by testing sets of 20 binary anion-π complexes of fluoride, chloride, bromide, nitrate, or carbonate ions with hexafluorobenzene, 1,3,5-trifluorobenzene, 2,4,6-trifluoro-1,3,5-triazine, or 1,3,5-triazine and 30 ternary π-anion-π' sandwich complexes composed from the same monomers, we suggest domain-based local-pair natural orbital coupled cluster energies extrapolated to the complete basis-set limit as reference values. We give a detailed explanation of the origin of anion-π interactions, using the permanent quadrupole moments, static dipole polarizabilities, and electrostatic potential maps. We use symmetry-adapted perturbation theory (SAPT) to calculate the components of the anion-π interaction energies. We examine the performance of the direct random phase approximation (dRPA), the second-order screened exchange (SOSEX), local-pair natural-orbital (LPNO) coupled electron pair approximation (CEPA), and several dispersion-corrected density functionals (including generalized gradient approximation (GGA), meta-GGA, and double hybrid density functional). The LPNO-CEPA/1 results show the best agreement with the reference results. The dRPA method is only slightly less accurate and precise than the LPNO-CEPA/1, but it is considerably more efficient (6-17 times faster) for the binary complexes studied in this paper. For 30 ternary π-anion-π' sandwich complexes, we give dRPA interaction energies as reference values. The double hybrid functionals are much more efficient but less accurate and precise than dRPA. The dispersion-corrected double hybrid PWPB95-D3(BJ) and B2PLYP-D3(BJ) functionals perform better than the GGA and meta-GGA functionals for the present test set.

Construction and application of a new dual-hybrid random phase approximation.

The direct random phase approximation (dRPA) combined with Kohn-Sham reference orbitals is among the most promising tools in computational chemistry and applicable in many areas of chemistry and physics. The reason for this is that it scales as N(4) with the system size, which is a considerable advantage over the accurate ab initio wave function methods like standard coupled-cluster. dRPA also yields a considerably more accurate description of thermodynamic and electronic properties than standard density-functional theory methods. It is also able to describe strong static electron correlation effects even in large systems with a small or vanishing band gap missed by common single-reference methods. However, dRPA has several flaws due to its self-correlation error. In order to obtain accurate and precise reaction energies, barriers and noncovalent intra- and intermolecular interactions, we construct a new dual-hybrid dRPA (hybridization of exact and semilocal exchange in both the energy and the orbitals) and test the performance of this new functional on isogyric, isodesmic, hypohomodesmotic, homodesmotic, and hyperhomodesmotic reaction classes. We also use a test set of 14 Diels-Alder reactions, six atomization energies (AE6), 38 hydrocarbon atomization energies, and 100 reaction barrier heights (DBH24, HT-BH38, and NHT-BH38). For noncovalent complexes, we use the NCCE31 and S22 test sets. To test the intramolecular interactions, we use a set of alkane, cysteine, phenylalanine-glycine-glycine tripeptide, and monosaccharide conformers. We also discuss the delocalization and static correlation errors. We show that a universally accurate description of chemical properties can be provided by a large, 75% exact exchange mixing both in the calculation of the reference orbitals and the final energy.

Accurate Complete Basis Set Extrapolation of Direct Random Phase Correlation Energies.

The direct random phase approximation (dRPA) is a promising way to obtain improvements upon the standard semilocal density functional results in many aspects of computational chemistry. In this paper, we address the slow convergence of the calculated dRPA correlation energy with the increase of the quality and size of the popular Gaussian-type Dunning's correlation consistent aug-cc-pVXZ split valence atomic basis set family. The cardinal number X controls the size of the basis set, and we use X = 3-6 in this study. It is known that even the very expensive X = 6 basis sets lead to large errors for the dRPA correlation energy, and thus complete basis set extrapolation is necessary. We study the basis set convergence of the dRPA correlation energies on a set of 65 hydrocarbon isomers from CH4 to C6H6. We calculate the iterative density fitted dRPA correlation energies using an efficient algorithm based on the CC-like form of the equations using the self-consistent HF orbitals. We test the popular inverse cubic, the optimized exponential, and inverse power formulas for complete basis set extrapolation. We have found that the optimized inverse power based extrapolation delivers the best energies. Further analysis showed that the optimal exponent depends on the molecular structure, and the most efficient two-point energy extrapolations that use X = 3 and 4 can be improved considerably by considering the atomic composition and hybridization states of the atoms in the molecules. Our results also show that the optimized exponents that yield accurate X = 3 and 4 extrapolated dRPA energies for atoms or small molecules might be inaccurate for larger molecules.

Atypical Antipsychotic Augmentation for Treatment-Resistant Depression: A Systematic Review and Network Meta-Analysis.

BACKGROUND: Previous meta-analyses of atypical antipsychotics for depression were limited by few trials with direct comparisons between two treatments. We performed a network meta-analysis, which integrates direct and indirect evidence from randomized controlled trials (RCTs), to investigate the comparative efficacy and tolerability of adjunctive atypical antipsychotics for treatment-resistant depression (TRD). METHODS: Systematic searches resulted in 18 RCTs (total n = 4422) of seven different types and different dosages of atypical antipsychotics and a placebo that were included in the review. RESULTS: All standard-dose atypical antipsychotics were significantly more efficacious than placebo in the efficacy (standardized mean differences [SMDs] ranged from -0.27 to -0.43). There were no significant differences between these drugs. Low-dose atypical antipsychotics were not significantly more efficacious than the placebo. In terms of tolerability, all standard-dose atypical antipsychotics, apart from risperidone, had significantly more side-effect discontinuations than placebo (odds ratios [ORs] ranged from 2.72 to 6.40). In terms of acceptability, only quetiapine (mean 250-350 mg daily) had significantly more all-cause discontinuation than placebo (OR = 1.89). In terms of quality of life/functioning, standard-dose risperidone and standard-dose aripiprazole were more beneficial than placebo (SMD = -0.38; SMD = -0.26, respectively), and standard-dose risperidone was superior to quetiapine (mean 250-350 mg daily). CONCLUSIONS: All standard-dose atypical antipsychotics for the adjunctive treatment of TRD are efficacious in reducing depressive symptoms. Risperidone and aripiprazole also showed benefits in improving the quality of life of patients. Atypical antipsychotics should be prescribed with caution due to abundant evidence of side effects.

The evaluation of family functioning by the family assessment device: a systematic review of studies in adult clinical populations.

A large body of research, documenting the impact of a family's functioning on health outcomes, highlights the importance of introducing the evaluation of patients' family dynamics into clinical judgment. The Family Assessment Device (FAD) is a self-report questionnaire designed to assess specific dimensions of family functioning. This qualitative systematic review, which follows PRISMA guidelines, aimed to identify the FAD's clinimetric properties and to report the incremental utility of its inclusion in clinical settings. A thorough literature search was performed, using both computerized and manual searches, yielding a total of 148 studies that were included in this review. The FAD has been extensively used in a variety of research contexts. In the majority of studies it was able to discriminate between clinical populations and controls and among groups of patients with different illnesses. The FAD also showed good test-retest and concurrent reliability, and modest sensitivity to change after treatment. FAD-dysfunctional family functioning was related to several patient clinical outcomes, including lower recovery rates and adherence to treatment, longer recovery time, poorer quality of life, and increased risk of relapse and drop-out. The present review demonstrates that the FAD is a suitable instrument for the evaluation of family functioning both in clinical and research settings.

The family assessment device: an update.

The current study set out to describe family functioning scores of a contemporary community sample, using the Family Assessment Device (FAD), and to compare this to a currently help-seeking sample. The community sample consisted of 151 families who completed the FAD. The help-seeking sample consisted of 46 families who completed the FAD at their first family therapy appointment as part of their standard care at an outpatient family therapy clinic at an urban hospital. Findings suggest that FAD means from the contemporary community sample indicate satisfaction with family functioning, while FAD scores from the help-seeking sample indicate dissatisfaction with family functioning. In addition, the General Functioning scale of the FAD continues to correlate highly with all other FAD scales, except Behavior Control. The cut-off scores for the FAD indicating satisfaction or dissatisfaction by family members with their family functioning continue to be relevant and the FAD continues to be a useful tool to assess family functioning in both clinical and research contexts.

Multicenter pilot treatment trial for psychogenic nonepileptic seizures: a randomized clinical trial.

IMPORTANCE: There is a paucity of controlled treatment trials for the treatment of conversion disorder, seizures type, also known as psychogenic nonepileptic seizures (PNES). Psychogenic nonepileptic seizures, the most common conversion disorder, are as disabling as epilepsy and are not adequately addressed or treated by mental health clinicians. OBJECTIVE: To evaluate different PNES treatments compared with standard medical care (treatment as usual). DESIGN, SETTING, AND PARTICIPANTS: Pilot randomized clinical trial at 3 academic medical centers with mental health clinicians trained to administer psychotherapy or psychopharmacology to outpatients with PNES. Thirty-eight participants were randomized in a blocked schedule among 3 sites to 1 of 4 treatment arms and were followed up for 16 weeks between September 2008 and February 2012; 34 were included in the analysis. INTERVENTIONS: Medication (flexible-dose sertraline hydrochloride) only, cognitive behavioral therapy informed psychotherapy (CBT-ip) only, CBT-ip with medication (sertraline), or treatment as usual. MAIN OUTCOMES AND MEASURES: Seizure frequency was the primary outcome; psychosocial and functioning measures, including psychiatric symptoms, social interactions, quality of life, and global functioning, were secondary outcomes. Data were collected prospectively, weekly, and with baseline, week 2, midpoint (week 8), and exit (week 16) batteries. Within-group analyses for each arm were performed on primary (seizure frequency) and secondary outcomes from treatment-blinded raters using an intention-to-treat analysis. RESULTS: The psychotherapy (CBT-ip) arm showed a 51.4% seizure reduction (P = .01) and significant improvement from baseline in secondary measures including depression, anxiety, quality of life, and global functioning (P < .001). The combined arm (CBT-ip with sertraline) showed 59.3% seizure reduction (P = .008) and significant improvements in some secondary measures, including global functioning (P = .007). The sertraline-only arm did not show a reduction in seizures (P = .08). The treatment as usual group showed no significant seizure reduction or improvement in secondary outcome measures (P = .19). CONCLUSIONS AND RELEVANCE: This pilot randomized clinical trial for PNES revealed significant seizure reduction and improved comorbid symptoms and global functioning with CBT-ip for PNES without and with sertraline. There were no improvements in the sertraline-only or treatment-as-usual arms. This study supports the use of manualized psychotherapy for PNES and successful training of mental health clinicians in the treatment. Future studies could assess larger-scale intervention dissemination. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00835627.

Using the tenets of the problem-centered systems therapy of the family (PCSTF) to teach the McMaster Approach to family therapists.

This article describes the videoconferencing training of a group of family therapists in the McMaster Approach to evaluating and treating families. A discussion of the key tenets of the McMaster Approach lays the groundwork for how these tenets were applied to training in a residential treatment agency for adolescents. The article serves as an example of how videoconference technology can facilitate extended training, even from a distance.

Nodes having a major influence to break cooperation define a novel centrality measure: game centrality.

Cooperation played a significant role in the self-organization and evolution of living organisms. Both network topology and the initial position of cooperators heavily affect the cooperation of social dilemma games. We developed a novel simulation program package, called 'NetworGame', which is able to simulate any type of social dilemma games on any model, or real world networks with any assignment of initial cooperation or defection strategies to network nodes. The ability of initially defecting single nodes to break overall cooperation was called as 'game centrality'. The efficiency of this measure was verified on well-known social networks, and was extended to 'protein games', i.e. the simulation of cooperation between proteins, or their amino acids. Hubs and in particular, party hubs of yeast protein-protein interaction networks had a large influence to convert the cooperation of other nodes to defection. Simulations on methionyl-tRNA synthetase protein structure network indicated an increased influence of nodes belonging to intra-protein signaling pathways on breaking cooperation. The efficiency of single, initially defecting nodes to convert the cooperation of other nodes to defection in social dilemma games may be an important measure to predict the importance of nodes in the integration and regulation of complex systems. Game centrality may help to design more efficient interventions to cellular networks (in forms of drugs), to ecosystems and social networks.

In situ liver transection with portal vein ligation for rapid growth of the future liver remnant in two-stage liver resection.

BACKGROUND: Portal vein embolization (PVE) has become a standard procedure to increase the future liver remnant (FLR) and enable curative resection of initially unresectable liver tumours. This study investigated the safety and feasibility of a new two-stage liver resection technique that uses in situ liver transection (ISLT) and portal vein ligation before completion hepatectomy. METHODS: A consecutive series of patients undergoing ISLT and extended right hepatectomy between 2009 and 2011 were compared with consecutive patients undergoing extended right hepatectomy after PVE. All patients had initially unresectable primary or secondary liver tumours, owing to an insufficient FLR (liver segments II/III). RESULTS: Fifteen patients who had PVE and seven who underwent ISLT before extended right hepatectomy were evaluated. ISLT induced rapid growth of the FLR within 3 days, particularly after insufficient PVE, from a mean(s.d.) of 293(58) ml to 477(85) ml, corresponding to a volume increase of 63(29) per cent. All patients who had ISLT underwent completion extended right hepatectomy within 8 days (range 4-8 days). CONCLUSION: ISLT is an effective and reliable technique to induce rapid growth of the FLR, even in patients with insufficient volume increase after PVE.

Performance of meta-GGA Functionals on General Main Group Thermochemistry, Kinetics, and Noncovalent Interactions.

Among the computationally efficient semilocal density functionals for the exchange-correlation energy, meta-generalized-gradient approximations (meta-GGAs) are potentially the most accurate. Here, we assess the performance of three new meta-GGAs (revised Tao-Perdew-Staroverov-Scuseria or revTPSS, regularized revTPSS or regTPSS, and meta-GGA made simple or MGGA_MS), within and beyond their "comfort zones," on Grimme's big test set of main-group molecular energetics (thermochemistry, kinetics, and noncovalent interactions). We compare them against the standard Perdew-Burke-Ernzerhof (PBE) GGA, TPSS, and Minnesota M06L meta-GGAs, and Becke-3-Lee-Yang-Parr (B3LYP) hybrid of GGA with exact exchange. The overall performance of these three new meta-GGA functionals is similar. However, dramatic differences occur for different test sets. For example, M06L and MGGA_MS perform best for the test sets that contain noncovalent interactions. For the 14 Diels-Alder reaction energies in the "difficult" DARC subset, the mean absolute error ranges from 3 kcal mol(-1) (MGGA_MS) to 15 kcal mol(-1) (B3LYP), while for some other reaction subsets the order of accuracy is reversed; more generally, the tested new semilocal functionals outperform the standard B3LYP for ring reactions. Some overall improvement is found from long-range dispersion corrections for revTPSS and regTPSS but not for MGGA_MS. Formal and universality criteria for the functionals are also discussed.

Density functionals that recognize covalent, metallic, and weak bonds.

Computationally efficient semilocal approximations of density functional theory at the level of the local spin density approximation (LSDA) or generalized gradient approximation (GGA) poorly describe weak interactions. We show improved descriptions for weak bonds (without loss of accuracy for strong ones) from a newly developed semilocal meta-GGA (MGGA), by applying it to molecules, surfaces, and solids. We argue that this improvement comes from using the right MGGA dimensionless ingredient to recognize all types of orbital overlap.