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标题: 求助AV1245指数的正负值比较大小 [打印本页]

作者
Author: qianbao 时间: 2020-7-19 20:09
标题: 求助AV1245指数的正负值比较大小
http://bbs.keinsci.com/thread-15137-1-1.html使用Multiwfn计算AV1245指数研究大环的芳香性
老师好，我在学习上面帖子计算AV1245指数时，计算得到了负值，帖子中提到“数值越大说明共振效应越强，也因此暗示这些原子所在的环的相应区域的共轭效应比较强”
请问老师，负值算不算错误呢？负值和正值的比较是否要看负号（负数<正数）还是看绝对值的大小呢？
谢谢老师

作者
Author: sobereva 时间: 2020-7-19 21:37
带符号对比
先确保没用弥散函数（除非你用基于NAO形式算AV1245）
轻微的负值直接当成0

作者
Author: qianbao 时间: 2020-7-20 09:52

sobereva 发表于 2020-7-19 21:37
带符号对比
先确保没用弥散函数（除非你用基于NAO形式算AV1245）
轻微的负值直接当成0

谢谢老师
我用的简单的6-31G(d)基组

作者
Author: qianbao 时间: 2020-7-26 12:21

sobereva 发表于 2020-7-19 21:37
带符号对比
先确保没用弥散函数（除非你用基于NAO形式算AV1245）
轻微的负值直接当成0

还想继续请教老师，AV1245是否可以计算整个分子的共轭度呢，比如C60这样的一个球体，
我尝试将C60分子输入1-60 得到了具体数值：0.18713266
是否可以说C60分子的共轭为0.18713266呢？

11 AV1245 index (approximate multicenter bond order for large rings) and AVmin
11

                     ------- AV1245 and AVmin -------
Input index of the atoms in the order of connectivity, e.g. 2,3,7,18,19,20
To exit, input "q"
Hint: If input "d" and press ENTER button, then you can input the indices in ar
bitrary order because the actual order will be automatically guessed, however in
this case any atom should not connect to more than two atoms in the ring
d
Generating bonding relationship...
Note: If distance between two atoms is smaller than sum of their covalent radii
multiplied by  1.150, then they are regarded as bonded

Input index of the atoms, the order is arbitrary
For example: 1,3-4,6-8,10-14
1-60
The order of the atoms in the ring has been successfully identified

Number of selected atoms: 60
Atomic sequence:
   1    2    5 11    7    3    8 15 14 23 29 19
20 12 21 13    6    9    4 10 16 25 28 18
26 17 27 22 32 31 41 30 40 39 43 33
35 24 34 44 45 53 52 57 49 50 51 42
47 37 36 46 38 48 56 54 55 58 60 59

4-center electron sharing index of    1    2 11    7: 0.00361575
4-center electron sharing index of    2    5    7    3: 0.00362024
4-center electron sharing index of    5 11    3    8: 0.00105940
4-center electron sharing index of 11    7    8 15: 0.00027574
4-center electron sharing index of    7    3 15 14: -0.00176890
4-center electron sharing index of    3    8 14 23: 0.00027277
4-center electron sharing index of    8 15 23 29: -0.00031044
4-center electron sharing index of 15 14 29 19: -0.00004441
4-center electron sharing index of 14 23 19 20: -0.00004389
4-center electron sharing index of 23 29 20 12: -0.00031124
4-center electron sharing index of 29 19 12 21: 0.00084605
4-center electron sharing index of 19 20 21 13: -0.00031035
4-center electron sharing index of 20 12 13    6: -0.00004410
4-center electron sharing index of 12 21    6    9: -0.00004368
4-center electron sharing index of 21 13    9    4: -0.00031074
4-center electron sharing index of 13    6    4 10: 0.00084606
4-center electron sharing index of    6    9 10 16: -0.00031066
4-center electron sharing index of    9    4 16 25: -0.00030995
4-center electron sharing index of    4 10 25 28: 0.00027433
4-center electron sharing index of 10 16 28 18: -0.00176526
4-center electron sharing index of 16 25 18 26: 0.00027733
4-center electron sharing index of 25 28 26 17: -0.00030997
4-center electron sharing index of 28 18 17 27: -0.00031009
4-center electron sharing index of 18 26 27 22: 0.00084475
4-center electron sharing index of 26 17 22 32: -0.00031005
4-center electron sharing index of 17 27 32 31: -0.00031014
4-center electron sharing index of 27 22 31 41: 0.00084460
4-center electron sharing index of 22 32 41 30: -0.00031012
4-center electron sharing index of 32 31 30 40: -0.00031028
4-center electron sharing index of 31 41 40 39: 0.00084487
4-center electron sharing index of 41 30 39 43: -0.00030996
4-center electron sharing index of 30 40 43 33: -0.00031009
4-center electron sharing index of 40 39 33 35: 0.00084455
4-center electron sharing index of 39 43 35 24: -0.00031006
4-center electron sharing index of 43 33 24 34: -0.00031013
4-center electron sharing index of 33 35 34 44: 0.00027686
4-center electron sharing index of 35 24 44 45: -0.00176906
4-center electron sharing index of 24 34 45 53: 0.00027381
4-center electron sharing index of 34 44 53 52: -0.00030978
4-center electron sharing index of 44 45 52 57: -0.00031072
4-center electron sharing index of 45 53 57 49: 0.00084588
4-center electron sharing index of 53 52 49 50: -0.00031072
4-center electron sharing index of 52 57 50 51: -0.00004455
4-center electron sharing index of 57 49 51 42: -0.00004463
4-center electron sharing index of 49 50 42 47: -0.00031058
4-center electron sharing index of 50 51 47 37: 0.00084600
4-center electron sharing index of 51 42 37 36: -0.00031042
4-center electron sharing index of 42 47 36 46: -0.00004437
4-center electron sharing index of 47 37 46 38: -0.00004392
4-center electron sharing index of 37 36 38 48: -0.00031124
4-center electron sharing index of 36 46 48 56: 0.00027371
4-center electron sharing index of 46 38 56 54: -0.00177605
4-center electron sharing index of 38 48 54 55: 0.00027353
4-center electron sharing index of 48 56 55 58: 0.00106050
4-center electron sharing index of 56 54 58 60: 0.00361770
4-center electron sharing index of 54 55 60 59: 0.00361581
4-center electron sharing index of 55 58 59    1: 0.00000972
4-center electron sharing index of 58 60    1    2: -0.00004059
4-center electron sharing index of 60 59    2    5: -0.00004058
4-center electron sharing index of 59    1    5 11: 0.00000971

AV1245 times 1000 for the selected atoms is 0.18713266
AVmin times 1000 for the selected atoms is    0.009712 ( 59 1 5 11)

                     ------- AV1245 and AVmin -------
Input index of the atoms in the order of connectivity, e.g. 2,3,7,18,19,20
To exit, input "q"
Hint: If input "d" and press ENTER button, then you can input the indices in ar
bitrary order because the actual order will be automatically guessed, however in
this case any atom should not connect to more than two atoms in the ring

作者
Author: sobereva 时间: 2020-7-26 21:01

qianbao 发表于 2020-7-26 12:21
还想继续请教老师，AV1245是否可以计算整个分子的共轭度呢，比如C60这样的一个球体，
我尝试将C60分子 ...

这么算没有意义

作者
Author: qianbao 时间: 2020-7-27 10:01

sobereva 发表于 2020-7-26 21:01
这么算没有意义

1、请问老师是指算整个分子的共轭没有意义还是我上述的计算做法没有意义呢？
2、如果是我不能用AV1245计算，那么是否有其他方法呢？

作者
Author: sobereva 时间: 2020-7-28 05:43

qianbao 发表于 2020-7-27 10:01
1、请问老师是指算整个分子的共轭没有意义还是我上述的计算做法没有意义呢？
2、如果是我不能用AV1245计 ...

不适合用于球形体系，而只能用于环
球形芳香性专门有别的方法讨论，google一搜一堆

作者
Author: 杜纪宽 时间: 2024-12-11 22:46

sobereva 发表于 2020-7-28 05:43
不适合用于球形体系，而只能用于环
球形芳香性专门有别的方法讨论，google一搜一堆

您好，我请问一下如果我计算一个苯并咔唑的AV1245常数，我可以进行一个整体计算嘛？还是去找适当的共轭途径，这两种哪种更贴切实际。还有就是我是拿优化好的基态就可以计算了，还是拿其他的激发态比如单线态激发态或者三线态的激发态。可能问的有点蠢，您别介意

作者
Author: sobereva 时间: 2024-12-11 23:41

杜纪宽发表于 2024-12-11 22:46
您好，我请问一下如果我计算一个苯并咔唑的AV1245常数，我可以进行一个整体计算嘛？还是去找适当的共轭途 ...

没有“常数”这种称呼

“整体计算”语义不明。直接算多中心键级就完了，对你感兴趣的共轭路径计算

若无特殊情况当然用基态极小点的基态波函数做计算

作者
Author: 杜纪宽 时间: 2024-12-12 09:16

sobereva 发表于 2024-12-11 23:41
没有“常数”这种称呼

“整体计算”语义不明。直接算多中心键级就完了，对你感兴趣的共轭路径计算

比如苯并咔唑这种材料，我能不能全选C与N原子计算AV1245指数，然后以此来衡量它的共轭程度

作者
Author: sobereva 时间: 2024-12-12 09:20

杜纪宽发表于 2024-12-12 09:16
比如苯并咔唑这种材料，我能不能全选C与N原子计算AV1245指数，然后以此来衡量它的共轭程度

不能
对这种情况本来就没法确切定义共轭程度。用LOL-pi分析，根据最小的二分点数值讨论倒是一定程度上可以
在Multiwfn中单独考察pi电子结构特征
http://sobereva.com/432（http://bbs.keinsci.com/thread-10610-1-1.html）

作者
Author: 杜纪宽 时间: 2024-12-12 09:21

sobereva 发表于 2024-12-12 09:20
不能

能请教一下如何去衡量嘛

作者
Author: 杜纪宽 时间: 2024-12-12 09:34

sobereva 发表于 2024-12-12 09:20
不能
对这种情况本来就没法确切定义共轭程度。用LOL-pi分析，根据最小的二分点数值讨论倒是一定程度上可 ...

谢谢您

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