A modified multi-reference second order perturbation theory  

作　　者：LI AnYang1, HAN HuiXian2, SUO BingBing3, WANG YuBin3 & WEN ZhenYi3 1Institute of Computational Chemistry, Chongqing University of Post and Telecommunications, Chongqing 400065, China 2Department of Physics, Northwest University, Xi’ an 710069, China 3Institute of Modern Physics, Northwest University, Xi’ an 710069, China 

出　　处：《Science China Chemistry》2010年第4期933-939,共7页中国科学（化学英文版）

基　　金：Supported by the National High Technical Development Project (863 project) Foundation (Grant No. 2006AA01A119);the National Natural Science Foundation of China (Grant No. 20773168);the Natural Science Foundation of CQUPT (A2008-36)

摘　　要：A new scheme with extended model space is proposed to improve the calculation of multi-reference second order perturbation theory (MRPT2). The new scheme preserves the concise code structure of the original program, and avoids intruder states in constructions of the potential energy surface, which is confirmed by a series of comparable calculations. The new MRPT2 program is an available tool for the research of molecular excited states and electronic spectrum.A new scheme with extended model space is proposed to improve the calculation of multi-reference second order perturbation theory (MRPT2). The new scheme preserves the concise code structure of the original program, and avoids intruder states in constructions of the potential energy surface, which is confirmed by a series of comparable calculations. The new MRPT2 program is an available tool for the research of molecular excited states and electronic spectrum.

关 键 词：PERTURBATION theory MULTI-REFERENCE INTRUDER STATE 

分 类 号：O641.122[理学—物理化学]