高等学校化学研究 ›› 2025, Vol. 41 ›› Issue (5): 1100-1105.doi: 10.1007/s40242-025-5172-z
YING Fuming, ZHOU Chen, WU Wei
YING Fuming, ZHOU Chen, WU Wei
摘要: We present a novel breathing orbital valence bond (BOVB) scheme, termed generalized BOVB (GBOVB), which constructs the wave function as a linear combination of valence bond self-consistent field (VBSCF) and its excited structures without requiring SCF orbital optimization. By applying different truncation levels to the excited configurations, multiple GBOVB variants are developed, offering flexible trade-offs between computational efficiency and accuracy. Benchmark tests reveal that GBOVB4 achieves the highest accuracy at a greater computational cost, while GBOVB4(D) provides the best balance between performance and efficiency. Notably, GBOVB overcomes convergence challenges of conventional BOVB methods when dealing with delocalized orbitals. Despite these advantages, limitations remain: excitations beyond double excitations may be important, and neglecting interactions between doubly excited structures in GBOVB4(D) can reduce accuracy, especially for systems with large active spaces.