关于双自由基体系的计算讨论

malong

我这边计算的是一个双自由基体系，分别用rb3lyp和ub3lyp进行了计算。结果显示用ub3lyp加guess=mix计算得到的自旋极化单重态能量（或者可以说破缺态）能量低6kcal/mol左右，这是不是间接说明rb3lyp计算得到的是波函数的鞍点，其波函数是不稳定的，因为我对用rb3lyp优化的结构进行波函数稳定性测试的时候显示了“#p freq b3lyp/6-31g(d) stable  Illegal IType or MSType generated byparse”的错误。双自由基体系也可以写成双离子的形式，从化学的角度而言这种上自由发生分子内电子转移形成双离子可行不？如果可行我们如果设置优化双离子形势的分子呢？还是优化出来的双自由体系能量是最稳定的基态双离子形势是不会出现的呢？从计算的角度如何表现双自由向双离子转化的这种能力呢？

sobereva

说r的不稳定就完了，不要去用鞍点这种描述。
freq和stable任务不要搅合在一起

别去考虑什么“双离子”，量化计算上也不用这种描述。怎么恰当计算这里已经写明了
谈谈片段组合波函数与自旋极化单重态
http://sobereva.com/82
CASSCF计算双自由基以及双自由基特征的计算
http://sobereva.com/264（http://bbs.keinsci.com/thread-322-1-1.html）

malong

sob，你好这个基于alpha和beta轨道的重叠积分来算双自由基特征，这个重叠积分怎么看呢，到底是哪一个？ 是第15号轨道吗Overlap between the     1th alpha and beta orbitals:    1.000000
Overlap between the     2th alpha and beta orbitals:    1.000000
Overlap between the     3th alpha and beta orbitals:    1.000000
Overlap between the     4th alpha and beta orbitals:    1.000000
Overlap between the     5th alpha and beta orbitals:    1.000000
Overlap between the     6th alpha and beta orbitals:    1.000000
Overlap between the     7th alpha and beta orbitals:    1.000000
Overlap between the     8th alpha and beta orbitals:    1.000000
Overlap between the     9th alpha and beta orbitals:    1.000000
Overlap between the    10th alpha and beta orbitals:    1.000000
Overlap between the    11th alpha and beta orbitals:    1.000000
Overlap between the    12th alpha and beta orbitals:    1.000000
Overlap between the    13th alpha and beta orbitals:    0.999849
Overlap between the    14th alpha and beta orbitals:    0.999722
Overlap between the    15th alpha and beta orbitals:    0.066251
Overlap between the    16th alpha and beta orbitals:    0.000073
Overlap between the    17th alpha and beta orbitals:    0.000026
Overlap between the    18th alpha and beta orbitals:    0.336487
Overlap between the    19th alpha and beta orbitals:   -0.335512
Overlap between the    20th alpha and beta orbitals:   -0.000481
Overlap between the    21th alpha and beta orbitals:    0.000489
Overlap between the    22th alpha and beta orbitals:    1.000000
Overlap between the    23th alpha and beta orbitals:    0.999992
Overlap between the    24th alpha and beta orbitals:    0.999877
Overlap between the    25th alpha and beta orbitals:    0.999885
Overlap between the    26th alpha and beta orbitals:    0.998657
Overlap between the    27th alpha and beta orbitals:    0.999916
Overlap between the    28th alpha and beta orbitals:    0.998642
Overlap between the    29th alpha and beta orbitals:    0.999307
Overlap between the    30th alpha and beta orbitals:    0.999421
Overlap between the    31th alpha and beta orbitals:    0.997187
Overlap between the    32th alpha and beta orbitals:    0.998308
Overlap between the    33th alpha and beta orbitals:   -0.988066
Overlap between the    34th alpha and beta orbitals:    0.997569
Overlap between the    35th alpha and beta orbitals:   -0.961387
Overlap between the    36th alpha and beta orbitals:    0.954262
Overlap between the    37th alpha and beta orbitals:    0.996707
Overlap between the    38th alpha and beta orbitals:    0.989572
Overlap between the    39th alpha and beta orbitals:    0.994715