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jiqiang

木虫 (正式写手)

[求助] 求帮解答一个审稿人的问题,用gaussian 09结构优化,计算理论值的基本参数设置问题

最近投了一个垃圾文章,之前被拒7次后这次意外让大修,里面有一个计算的问题对本人来说非常棘手,本人对计算确实不太懂,而且计算这块原来是师兄算的,现在师兄毕业,我对这问题更无解了,审稿人评论和问题简介如下:
      This manuscript reports on the synthesis and characterization using usual spectroscopic techniques of two novel cationic cyclopentadienyl-iron-arene complexes containing triphenyl butene substituent as well as their nucleophilic hydroxyl organic precursors. In addition, the optical properties of the mixed sandwich compounds were studied both experimentally and theoretically (DFT/B3LYP and TD-DFT) methods).
     问题:7) the authors should be aware that the dipole moment of an ion is not invariant with respect to a change of the origin. Have they tried to calculate the hyperpolarizabilities with different choices of origin?
下面是部分计算源程序内容:
里面一种物质的Z构型的部分内容:
%nosave
%chk=D:\calculation(Junru Han)\2.chk
%mem=1GB
# opt freq=savenormalmodes b3pw91/lanl2dz guess=(mix,local,save) pop=npa
geom=connectivity scfcon=8

Title Card Required

1 1
C                 -0.29761905    0.00000000    0.00000000
C                 -1.00186977   -0.10291912    1.19379033
C                 -0.36969614    0.18339069    2.40414775
C                  0.95935295    0.57603500    2.41930512
C                  1.67668178    0.68083245    1.22976466
C                  1.04456758    0.39048709    0.01315648
……
另一个E型部分内容:
%nosave
%chk=D:\try2\mo\1.chk
# rb3lyp/genecp pop=full

Title Card Required

1 1
C                 -0.50477747    0.14851485   -0.01321806
C                 -1.87921347    0.43661585    0.14665494
C                 -2.27681547    1.37158985    1.13107394
C                 -1.30983147    2.02649885    1.92557894
C                  0.07722353    1.81381085    1.69965394
……
C Cl O H 0
6-31g**
****
Fe 0
lanl2dz
****

Fe 0
lanl2dz

两个文件计算要求差别大,这个我也不知道师兄当时怎么弄的,不过大致的参数可以看出了。结构优化是用的学校云计算平台算的,再用实验室电脑做的单点能计算~~好像是这样~~

下面是文章的部分内容,希望对应助有帮助~~
The positive solvatochromism of the UV-Vis absorption of TPE-Fcs upon the increase in solvent polarity was found from the experiment. Quantum chemical calculations of the orbital energy, geometrical structure, absorption spectra, and first hyperpolarizability (β) values of the TPE-Fcs were carried out using density functional (DFT/B3LYP and TD-DFT) methods. The experimental results showed that the observed spectra were in good agreement with the calculated values. The calculated HOMO and LUMO energies showed that the compounds exhibit charge transfer that mediated by the metal center.
……
In the present work, we have used density functional theory (DFT) at the Becke 3-Lee-Yang-Parr (B3LYP)/Genecp (Fe with Lanl2dz basis set and C, H, N, and O with 6-31G** basic set) basis set level for the computation of molecular structure and energies of the optimized structures in the ground state. The entire calculations were performed by using Gaussian09 program package. The absorption spectra of TPE-Fcs were calculated using the time-dependent density functional theory (TD-DFT) method from the gas phase optimized geometries.
……
The enhancement of charge separation is known to favor large NLO responses. The electrostatic first hyperpolarizability (β) was calculated using the Gaussian 09 package. Based on the calculated electronic properties and geometries, the electrostatic first hyperpolarizability βμ were calculated using the DFT/B3LYP method. The βμ of the title compounds are shown in Table 4. The second-order optical susceptibility of the target compounds followed the order: βμ (TPE) < βμ (TPE-Fc) and βμ (Z) < βμ (E). This trend is attributed to the intermolecular charge-transfer of the TPE-Fc compounds. In the presence of the electron-rich diphenyl ether and diphenyl sulfide moiety as a strong donor-group and the cationic cyclopentadienyliron fragment as a strong acceptor-group led to a larger value of βμ (TPE-Fcs) than our previous study. This switching of electron delocalization directly affected the NLO coefficient, which could generate push–pull systems. Such systems favor the generation of large NLO responses.  

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jiqiang

木虫 (正式写手)

希望高人能给个专业又能让审稿人满意的答案,还有最好能写成英文的答案,以免我缺少计算专业知识而在翻译过程中产生误解或不准确的情况,在此谢过了~~
2楼2014-02-22 11:35:24
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jiqiang

木虫 (正式写手)

The dipole moment (μ), mean polarizability (α), and total first static hyperpolarizability (β) of TPE-Fcs were calculated in terms of x, y, z components, which are given by the following equations:
μ=(μx2+μy2+μz2)1/2       (1)
α=(αxx+αyy+αzz)/3       (2)
β=(βx2+βy2+βz2)1/2       (3)
βj=βjjj+∑(βjii+2βijj)/3   (i≠j; i, j=x, y, z)
  The β components of Gaussian output are reported on atomic units and therefore the calculated β components have been converted into electrostatic units βtot(esu) (1 a.u.=8.6393×10-33esu)[31].
上次忘记给出这些内容了,问题应该是来自这儿的!!!
3楼2014-02-24 23:10:15
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