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标题: 关于Orca4.2和Grimme官网预编译dtfd4 2.0的半数值hessian结果的疑问 [打印本页]

作者
Author: norlandn 时间: 2019-8-15 09:31
标题: 关于Orca4.2和Grimme官网预编译dtfd4 2.0的半数值hessian结果的疑问
最近看D4色散校正的一些东西，刚好Orca 4.2发布了，试了Orca 4.2和Grimme官网预编译dtfd4 2.0的D4校正，发现半数值hessian结果完全不一样，还试了Sobereva老师编译的dftd4和本人编译的（gfortran 8.3），每个版本的hessian结果都不一样。。。感觉Orca 4.2的结果是合理的，其他的都偏太大了。

我的问题是：如果有解析梯度没有解析力常数，怎么用半数值方法计算hessian？或者哪本书里面有相关内容？谢谢！

下面贴一下计算结果（CH3COO-）：
1. Orca 4.2 输入文件：
------------------------------------------------------------------------------------------
!B3LYP D4 def2-SVP pal4 largeprint
!Opt freq
%maxcore 1600 #memory per core

* xyz -1 1
C                -2.98385104 1.10276924 -0.02471012
H                -2.31278441 0.27556795 -0.12623650
H                -2.87483537 1.75573684 -0.86533423
H                -3.99035561 0.74226683 0.01872449
C                -2.65797225 1.87238941 1.26876884
O                -2.17427191 1.26364130 2.25822842
O                -2.90503001 3.27879594 1.34547055
*

------------------------------------------------------------------------------------------

2. Orca 4.2 计算结果：
------------------------------------------------------------------------------------------
Dispersion correction Hessian from Numerical Differentiation:
               0       1       2       3       4       5
   0    -0.000000 0.000000 0.000000 0.000000 0.000010 0.000000
   1    0.000000 0.000000 0.000000 0.000000  -0.000004 0.000000
   2    0.000000 0.000000 0.000000 0.000000  -0.000022 0.000000
   3    0.000000 0.000000 0.000000 0.000000  -0.000048 0.000000
   4    0.000010  -0.000004  -0.000022  -0.000048 0.000088 0.000000
   5    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   6    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   7    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   8    -0.000003 0.000003  -0.000019  -0.000005 0.000003 0.000002
   9    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   10    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   11    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   12    0.000013 0.000000  -0.000003  -0.000010  -0.000001 0.000000
   13    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   14    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
   15    0.000000 0.000000 0.000000 0.000000 0.000000 0.000000

------------------------------------------------------------------------------------------

3. Orca 4.2优化xyz（dftd4.2.0输入文件）
------------------------------------------------------------------------------------------
7
Coordinates from ORCA-job
  C -2.96234747221516    1.13753657518641    -0.00594295815634
  H -2.30512884148872    0.25706230511390    -0.11381708705029
  H -2.88260252193163    1.78761563698931    -0.89530293029478
  H -4.00473208412876    0.76695030063883    0.03760679257932
  C -2.64155550608230    1.93768988820903    1.31782030969296
  O -2.17769905829250    1.24920547470040    2.25319458796829
  O -2.92503511586093    3.15510732916212    1.28135273526085

------------------------------------------------------------------------------------------

4. 官方预编译dftd4计算结果

dftd4.2.0 t.xyz -c -1 -f b3lyp --hess -v

------------------------------------------------------------------------------------------
         -------------------------------------------------
      |             numerical hessian             |
         -------------------------------------------------
# NOTE: Printing only the lower triangle
# Hdisp fmt=' %22.14lf  %22.14lf  %22.14lf '
   -0.00010345273715       0.19976470366332    -0.00005346853929
   0.42008435882198       0.22030842641212    -0.00000101238162
   -0.20482856769357    -0.40465866585848    -0.62492083164259
   -0.00000662559374       0.34949769044462       0.14976453567530
   -0.07054698539576       0.55438861792707    -0.00004004810093
   0.30687377339114       0.10709184106419    -0.11319126167408
   0.51172465480829    -0.04266357686311       0.00005180796368
   -0.05129384135606    -0.25108264304861    -0.47136980185020
   0.15354694292158    -0.40083577724153    -0.35814736915823
   0.00002587701509    -0.05548564682566    -0.25525651727032
   -0.47558073703878       0.14935652501056    -0.40502873811310
   -0.36233697403712    -0.00417973586309       0.00000162037197
   0.51434934219046       0.31454078529362       0.09431464328415
   0.71919752752026       0.16481069413987       0.20750000308162
   0.56566214517322       0.56987171335137    -0.00002302891487
   0.26529187670798       0.06547179977441    -0.15482855013523
   0.47008771733844    -0.08429771455301    -0.04160639535621
   0.31655232148891       0.32073355805260    -0.24912088707005
------------------------------------------------------------------------------------------

作者
Author: sobereva 时间: 2019-8-16 07:40
知道什么叫有限差分，就知道怎么根据一阶导数算数值二阶导数。wiki上一搜数值导数或有限差分就有

8成是dftd4程序有限差分代码有bug

作者
Author: norlandn 时间: 2019-8-16 12:57
大概明白了，感谢老师！

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