ORCA 建议部分使用相对论计算代替赝势是否合理？ - 计算化学公社

General recommendations
- If your molecule does not contain elements heavier than Kr, then you typically should not use an ECP. Stick with an all-electron approach so as not to not sacrifice accuracy for marginal speed-up.
- If your molecule contains one heavy element (heavier than Kr), e.g. in a typical transition metal complex, there is probably not a big advantage to using an ECP. You may get more accurate results and almost as fast, using an all-electron relativistic approximation instead.
- If the molecule contains many heavy elements (heaver than Kr), then ECPs have their greatest advantage and efficient geometry optimizations can be performed. Single-point calculations using an all-electron scalar relativistic approach might then be a good idea for even more accurate energies or property calculations.
- There are also cases where one is dealing with so heavy elements that one runs into numerical problems when using an all-electron scalar relativistic method (ZORA, DKH). Using an ECP might then be preferred.

第一过渡系用全电子基组（用ECP节省不了多少时间）
有一个2/3过渡系原子，推荐使用全电子相对论近似（用ECP不会有很大优势）
有很多2/3过渡系原子，用ECP计算，最后用全电子标量相对论计算可以提高精度。
如果标量相对论效应有数值问题，则换用ECP

sobereva 发表于 2015-10-27 15:47
说法基本合理。不过对于第一周期过渡金属，用赝势也还是能省不少时间的。
用全电子标量相对论计算本身比赝 ...

清微发表于 2018-1-5 22:56
老师，在高斯中DKH2和DKH是同义词，但DKH和DK含义完全不同，据我的理解，DK是把Dirac方程转化为二分量，属 ...

rayinyin 发表于 2018-5-4 10:46
楼上的讨论是否主要针对DFT，如果是波函数的计算，还有相应grid的设置的必要吗？

rayinyin 发表于 2018-5-7 09:50
rijcosx方法需要设置一个gridx参数，如果是RI-JK加速于波函数方法的话，还需要设置grid相关的参数否？