title: New implementations of MRCI in semiempirical frameworks.
abstract: Multireference configuration interaction with single and double excitations (MRCISD) as well as its analytic CI gradients has been implemented in the semiempirical framework. The hole-particle symmetry and a mixed driven model for computing coupling coefficients have been used in the new code that allows us to perform MRCI and gradient calculations with higher efficiency and less storage requirements.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, The College of Chemistry and Materials Science, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Northwest University, Xi'an 710069, People's Republic of China.
authors.forename: Yibo
authors.initials: Y
authors.lastname: Lei
authors.forename: Bingbing
authors.initials: B
authors.lastname: Suo
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Dou
authors.forename: Yubin
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhenyi
authors.initials: Z
authors.lastname: Wen