Charge Models# 电荷模型

Minimal Basis Iterative Stockholder (MBIS)#
最小基迭代股东(MBIS)

The Minimal Basis Iterative Stockholder (MBIS) [Ayers2016] method is a variant of the Hirshfeld method. The idea behind this approach is to expand the pro-atomic density in a minimal set of atom-centered s-type Slater functions. MBIS is used in various applications like Force-Field parameterization or rescaling atomic polarizabilities.
最小基集迭代股东(MBIS)[Ayers2016]方法是 Hirshfeld 方法的一种变体。该方法的核心思想是将原子密度在最小的一组原子中心 s 型 Slater 函数中展开。MBIS 被广泛应用于力场参数化或原子极化率的重标定等应用中。

MBIS charges can easily be requested by the simple input keyword MBIS:
MBIS 费用可以通过简单输入关键词 MBIS 轻松请求:

!wB97X-V DEF2-TZVP MBIS

Within ORCA its also possible to compute atomic dipole-, quadrupole-, and octupolemoments within the MBIS scheme. These can be printed via the extended output option:
在 ORCA 中,还可以通过 MBIS 方案计算原子的偶极矩、四极矩和八极矩。这些可以通过扩展输出选项进行打印:

%method
MBIS_LARGEPRINT TRUE  # default = FALSE 
end

There are various further options to use with MBIS that can be found in the ORCA manual.
在 ORCA 手册中可以找到与 MBIS 结合使用的各种进一步选项。

Example: 5,6-diaminobenzene-2,3-dicarbonitrile#
示例:5,6-二氨基苯-2,3-二腈

In this example, we will compute MBIS properties for 5,6-diaminobenzene-2,3-dicarbonitrile. This molecules has, for a neutral compound, a high experimental dipole moment of 10.5±0.2 Debye [Müllen2016].
在此示例中,我们将计算 5,6-二氨基苯-2,3-二腈的 MBIS 性质。对于中性化合物而言,该分子具有较高的实验偶极矩,为 10.5±0.2 德拜[Müllen2016]。

../_images/mbis-example-2.png

Figure: Molecular structure of 5,6-diaminobenzene-2,3-dicarbonitrile.
图:5,6-二氨基苯-2,3-二腈的分子结构。
#

To obtain the MBIS charges and atomic multipoles we can employ the following input:
为了获取 MBIS 电荷和原子多极矩,我们可以使用以下输入:

!wB97X-V DEF2-TZVP MBIS

%method
MBIS_LARGEPRINT TRUE  # default = FALSE
end

We can now find the MBIS charges in the output file basename.out:
我们现在可以在输出文件 basename.out 中找到 MBIS 费用:

------------------
MBIS ANALYSIS
------------------

Convergence threshold (charges)      ...        1.000e-06
Number of iterations                 ...        75

Total integrated alpha density       ...     40.999976141
Total integrated beta density        ...     40.999976141   

  ATOM     CHARGE    POPULATION     SPIN    
   0 N   -0.843167    7.843167    0.000000
   1 C    0.263784    5.736216    0.000000
   2 C    0.263771    5.736229    0.000000
   3 N   -0.843075    7.843075    0.000000
   4 C   -0.257113    6.257113    0.000000
   5 H    0.386416    0.613584    0.000000
   6 C   -0.027776    6.027776    0.000000
   7 C    0.356361    5.643639    0.000000
   8 C   -0.027781    6.027781    0.000000
   9 C    0.356301    5.643699    0.000000
  10 C   -0.257197    6.257197    0.000000
  11 H    0.386399    0.613601    0.000000
  12 H    0.384289    0.615711    0.000000
  13 N   -0.433371    7.433371    0.000000
  14 N   -0.433382    7.433382    0.000000
  15 H    0.384313    0.615687    0.000000
  16 H    0.170610    0.829390    0.000000
  17 H    0.170665    0.829335    0.000000

  TOTAL   0.000048   81.999952    0.000000

The charges mapped to to respective atoms are:
映射到各个原子的电荷为:

../_images/mbis-example-2-charges.png

Figure: MBIS charges mapped to the atoms in 5,6-diaminobenzene-2,3-dicarbonitrile.
图:MBIS 电荷映射到 5,6-二氨基苯-2,3-二腈中的原子。
#

As we requested the large printout we also find the atomic dipole-
正如我们请求的大幅打印,我们也发现了原子偶极子——

 MBIS ATOMIC DIPOLE MOMENT (A.U.):
  ATOM           X             Y             Z
   0 N      -0.038063     -0.015085     -0.103028
[...]

quadrupole-, and 四极-,以及

 MBIS ATOMIC QUADRUPOLE MOMENT (A.U.):
  ATOM          XX            YY            ZZ            XY            XZ            YZ
   0 N      -5.193045     -5.361150     -5.246319     -0.051568      0.008765      0.095347
[...]

octupole moments 八极矩

 MBIS ATOMIC OCTUPOLE MOMENT (A.U.):
  ATOM          XXX           YYY           ZZZ           XXY           XXZ           XYY           XYZ           XZZ           YYZ           YZZ
   0 N      -0.327968      0.057298     -0.069317     -0.055180     -0.039158     -0.006877      0.012999      0.314176     -0.394271     -0.035321
[...]

Note 注释

Note that there are various other charge models available within ORCA including Mulliken, Hirshfeld, and more.
请注意,ORCA 中还提供了多种其他电荷模型,包括 Mulliken、Hirshfeld 等。

Structures# 结构

5,6-diaminobenzene-2,3-dicarbonitrile
5,6-二氨基苯-2,3-二腈
18

  N       1.34721241437119     -0.19875204578868      2.39728170838216
  C       0.70867203692614     -0.08409568583235      1.17165794089898
  C      -0.69557523765992     -0.03503410755084      1.15547373801566
  N      -1.36695245837416     -0.05357620226644      2.36862799274125
  C      -1.35463448913564      0.08033827321651     -0.05146262039998
  H       2.34810629260485     -0.10903909384438      2.36022439042418
  C      -0.65492341506459      0.11650354440257     -1.24923904175946
  C      -1.38024608777480      0.22912849642218     -2.47568708881038
  C       0.73267914111713      0.02684352514116     -1.23535246715296
  C       1.49072510922012      0.04700848828691     -2.44697511349353
  C       1.40013842906872     -0.06847776855218     -0.02246437719730
  H      -2.36630779122682     -0.13781135092574      2.29511415417341
  H       0.95194597461754      0.38337577789381      3.11975943676764
  N      -1.98904585311221      0.31503849289177     -3.44573900381660
  N       2.12487320894712      0.06661771348260     -3.40431289691542
  H      -0.98996937874613     -0.71100834890760      3.03401439822709
  H      -2.43381979990049      0.12883159310508     -0.07188432898727
  H       2.47966190412196     -0.11602130117439     -0.01964682109748