A new algorithm for inactive orbital optimization in valence bond theory

作者：Chen ZhenHua; Zhang QianEr; Wu Wei^*

来源：Science in China Series B-Chemistry, 2009, 52(11): 1879-1884.

DOI：10.1007/s11426-009-0265-y

• valence bond theory
• non-orthogonal orbitals
• gradient

This paper presents an efficient algorithm for energy gradients in valence bond self-consistent field (VBSCF) method with non-orthogonal orbitals. The frozen core approximation method is extended to the case of non-orthogonal orbitals. The expressions for the total energy and its gradients are presented by introducing auxiliary orbitals, where inactive orbitals are orthogonal, while active orbitals are non-orthogonal themselves but orthogonal to inactive orbitals. It is shown that our new algorithm has a low scaling of (N-a + 1)m(4), where N-a and m are the numbers of the active orbitals and basis functions, respectively, and is more efficient than the existing VBSCF algorithms.

• 出版日期2009-11
• 单位厦门大学