ABSTRACT
State-specific complete active space self-consistent field (SS-CASSCF) theory has emerged as a promising route to accurately predict electronically excited energy surfaces away from molecular equilibria. However, its accuracy and practicality for chemical systems of photochemical interest have yet to be fully determined. We investigate the performance of the SS-CASSCF theory for the low-lying ground and excited states in the double bond rotation of ethylene. We show that state-specific approximations with a minimal (2e,2o) active space provide comparable accuracy to state-averaged calculations with much larger active spaces, while optimizing the orbitals for each excited state significantly improves the spatial diffusivity of the wave function. However, the incorrect ordering of state-specific solutions causes excited state solutions to coalesce and disappear, creating unphysical discontinuities in the potential energy surface. Our findings highlight the theoretical challenges that must be overcome to realize practical applications of state-specific electronic structure theory for computational photochemistry.
ABSTRACT
BACKGROUND: Early parenthood is a sensitive period for parents. Parents may feel uncertain about their new roles and unsure about where to find trusted information and support. The aim of this study was to explore the association between breastfeeding and early home visits and a proactive telephone support intervention and to describe parental experiences. METHOD: This study was conducted as a mixed method study with a convergent design using qualitative data from the written comments of parents, and the quantitative data consisted of demographics, breastfeeding, and Likert questions about parents' satisfaction with the early home visit and telephone support. Historic control (2017-2018) and intervention (2019-2020) data were collected from one family health care centre, and control (2019-2020) data were collected from another family health care centre. RESULTS: In total, 838 infants, 42 mothers and 38 fathers contributed to the data in the study. The intervention group had a statistically significantly earlier home visit than the control groups. Early home visits and proactive telephone support to parents with newborn infants were not associated with breastfeeding outcomes up to six months after birth, but we could not exclude the possibility that this was a consequence of our observational study design. However, the early home visit was appreciated by the parents where they received both practical and emotional support. CONCLUSIONS: Although the intervention was not associated with breastfeeding, the parents appreciated the service. This shows the importance of continuing to investigate how and which support parents of newborn infants need and the effects of such support, including interventions to provide optimal support to facilitate continued breastfeeding.
