摘要
Accurate evaluation of elec-tron correlations is essential for the reliable quantitative de-scription of electronic struc-tures in strongly correlated sys-tems,including bond-dissociat-ing molecules,polyradicals,large conjugated molecules,and transition metal complex-es.To provide a user-friendly tool for studying such challeng-ing systems,our team developed Kylin 1.0[J.Comput.Chem.44,1316(2023)],an ab initio quantum chemistry program designed for efficient density matrix renormalization group(DMRG)and post-DMRG methods,enabling high-accuracy calculations with large active spaces.We have now further advanced the software with the release of Kylin 1.3,featuring optimized DMRG algorithms and an improved tensor contraction scheme in the diagonaliza-tion step.Benchmark calculations on the Mn_(4)CaO_(5)cluster demonstrate a remarkable speed-up of up to 16 fater than Kylin 1.0.Moreover,a more user-friendly and efficient algorithm[J.Chem.Theory Comput.17,3414(2021)]for sampling configurations from DMRG wavefunc-tion is implemented as well.Additionally,we have also implemented a spin-adapted version of the externally contracted multi-reference configuration interaction(EC-MRCI)method[J.Phys.Chem.A 128,958(2024)],further enhancing the program’s efficiency and accuracy for electron correlation calculations.
精确的电子关联计算对于强关联体系(如键解离分子、多自由基体系、大共轭分子、过渡金属化合物)电子结构的可靠定量描述至关重要,为了给这些挑战性体系的研究提供一个用户友好的工具,作者团队开发了从头算量子化学程序Kylin1.o[J.Comput.Chem.44,1316(2023)].该程序为高效的密度矩阵重正化群和后密度矩阵重正化群方法设计,以实现大活性空间的高精度计算。最近,团队进一步开发了Kylin1.3版本:对密度矩阵重正化群方法的代码进行了优化,并在对角化步骤中采用改进的张量缩并顺序;经Mn4CaO5团簇的基准计算显示,与Kylin1.0相比,密度矩阵重正化群计算可显著提速16倍.对于密度矩阵重正化群波函数的组态采样,实现了一种更加高效和用户友好的算法[J.Chem.TheoryComput.17,3414(2021)].此外,还实现了自旋匹配版本的外收缩多参考组态相互作用方法[J.Phys.Chem.A128,958(2024)],进一步提高了程序在电子关联计算中的效率和准确性.
基金
supported by Shandong Provincial Nat-ural Science Foundation(ZR2024ZD30)
the National Natural Science Foundation of China(Nos.22325302 and 22403100).
