| 查看: 1240 | 回复: 1 | |||
| 当前主题已经存档。 | |||
[交流]
【求助】关于casscf方法计算激发态的活性空间选择
|
|||
 大家好，casscf方法计算激发态，最重要的是不是活性空间的选择？怎样选？然后又怎样选择调轨道呢？朋友们了解的，都过来说说你们的认识吧，谢谢。 |
回复此楼» 猜你喜欢
博士生招生, 材料模拟方向，University of South Carolina
已经有0人回复
-
Postdoc position, materials simulations/machine learning, U. of South Carolina
已经有0人回复
-
物理化学论文润色/翻译怎么收费?
已经有273人回复
-
祈福青基
已经有34人回复
-
牛来！米来！面来！
已经有8人回复
-
2027申博咨询
已经有11人回复
-
寻求CrC2Al的cif文件，感谢
已经有0人回复
-
求问：LATP煅烧应该使用什么容器？
已经有0人回复
-
ORCA 纯新手向入门指南0.7版
已经有0人回复
-
哈尔滨工业大学（深圳）绿色合成化学团队招收27年春季或秋季入学的博士生
已经有5人回复
-
吉林大学化学学院理论化学研究所刘靖尧教授课题组招收2027级申请考核制博士研究生
已经有0人回复
coolrainbow
木虫 (著名写手)
未来国家冻凉
- QC强帖: 11
- 应助: 1 (幼儿园)
- 贵宾: 0.1
- 金币: 3979.5
- 散金: 10
- 红花: 50
- 帖子: 1137
- 在线: 272.3小时
- 虫号: 239560
- 注册: 2006-04-07
- 性别: GG
- 专业: 理论和计算化学
★ ★ ★ ★ ★ ★
小木虫(金币+0.5):给个红包，谢谢回帖交流
yjcmwgk(金币+5,VIP+0): 12-29 09:56
小木虫(金币+0.5):给个红包，谢谢回帖交流
yjcmwgk(金币+5,VIP+0): 12-29 09:56
|
How to Choose Active Orbitals? There is no general answer to this question. Attempts have been made but with rather limited success. If you have no idea, choose a large active space and run RASSCF(SDTQ...) with only a small number of orbitals in RAS2. This has to be done on several points on an energy surface. Choose as active the orbitals with occupation numbers > 0:02 or < 1:98. If this is not possible, choose another method. Use the same active space for the whole surface. Excited States of Conjugated Organic Moelcules Use preferably all -orbitals. Add appropriate lone-pair orbitals. Add 3s,3p,3d Rydberg orbitals if the spectrum extends into this region. Note that this requires special basis sets. Sometimes it is necessary to add extra valence orbitals in order to avoid intruder states. Alternatively level shift can be used. Active Spaces in TM compounds For Mn-Cu use preferably 2 orbitals per doubly occupied 3d orbital (the double shell e ect). These may include ligand orbitals for bond forming 3d orbitals. This is enough for d-d transitions in ionic compounds (10 orbitals). If CT transitions, corresponding ligand orbital must be included. Sometimes it is not possible to nd an appropriate active space that is small enough! Core correlation and relativistic e ects are important already for the rst row of TM. |
2楼2009-12-28 17:48:02