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铜虫 (小有名气)

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注册: 2011-02-23
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专业: 水产基础生物学

[求助] 溶剂化能的计算

比如我想算3-溴苯甲酸(3-BBA)的电化学脱溴电位,通过以下的循环
3-BBA- + 2e- + H2O =BA- + OH- + Br-

3-BBA-gas(# opt freq b3lyp/6-311++g(d,p) pop=nbo)

Zero-point correction=                         0.090990 (Hartree/Particle)
Thermal correction to Energy=                   0.099484
Thermal correction to Enthalpy=                0.100428
Thermal correction to Gibbs Free Energy=       0.055531
Sum of electronic and zero-point Energies=       -2993.856342
Sum of electronic and thermal Energies=          -2993.847848
Sum of electronic and thermal Enthalpies=          -2993.846903
Sum of electronic and thermal Free Energies=       -2993.891801

3-BBA-solution (# opt freq b3lyp/6-311++g(d,p) scrf=(cpcm,solvent=water,read) pop=nbo)

Zero-point correction=                         0.090932 (Hartree/Particle)
Thermal correction to Energy=                   0.099342
Thermal correction to Enthalpy=                0.100287
Thermal correction to Gibbs Free Energy=       0.055291
Sum of electronic and zero-point Energies=       -2993.955046
Sum of electronic and thermal Energies=          -2993.946635
Sum of electronic and thermal Enthalpies=          -2993.945691
Sum of electronic and thermal Free Energies=       -2993.990687

溶剂化能=-2993.990687+-2993.891801=-0.098886 au

H20-gas(# opt freq b3lyp/6-311++g(d,p))
Zero-point correction=                         0.021289 (Hartree/Particle)
Thermal correction to Energy=                   0.024125
Thermal correction to Enthalpy=                0.025069
Thermal correction to Gibbs Free Energy=       0.003647
Sum of electronic and zero-point Energies=          -76.437242
Sum of electronic and thermal Energies=             -76.434406
Sum of electronic and thermal Enthalpies=          -76.433462
Sum of electronic and thermal Free Energies=       -76.454884

For the salvation Gibbs free energy of water (∆G_solv^0(H2O)), we used the standard Gibbs free energy of vaporisation at 298.15 K and 1 atm with a concentration of 1m: ∆G_solv^0(1M)=-6.3 kcal mol-1.

BA-gas(# opt freq b3lyp/6-31++g(d,p))

Zero-point correction=                         0.101650 (Hartree/Particle)
Thermal correction to Energy=                   0.108621
Thermal correction to Enthalpy=                0.109565
Thermal correction to Gibbs Free Energy=       0.069618
Sum of electronic and zero-point Energies=          -420.201997
Sum of electronic and thermal Energies=             -420.195027
Sum of electronic and thermal Enthalpies=          -420.194083
Sum of electronic and thermal Free Energies=       -420.234030

BA-solution (# opt freq b3lyp/6-311++g(d,p) scrf=(cpcm,solvent=water,read) )
Zero-point correction=                         0.101129 (Hartree/Particle)
Thermal correction to Energy=                   0.108074
Thermal correction to Enthalpy=                0.109018
Thermal correction to Gibbs Free Energy=       0.068733
Sum of electronic and zero-point Energies=          -420.400986
Sum of electronic and thermal Energies=             -420.394041
Sum of electronic and thermal Enthalpies=          -420.393097
Sum of electronic and thermal Free Energies=       -420.433382

G_solv^0=-420.433382+420.234030 =-0.199352 au

Br-gas(# opt freq b3lyp/6-311++g(d,p))
Zero-point correction=                         0.000000 (Hartree/Particle)
Thermal correction to Energy=                   0.001416
Thermal correction to Enthalpy=                0.002360
Thermal correction to Gibbs Free Energy=       -0.016176
Sum of electronic and zero-point Energies=       -2574.237796
Sum of electronic and thermal Energies=          -2574.236379
Sum of electronic and thermal Enthalpies=          -2574.235435
Sum of electronic and thermal Free Energies=       -2574.253971

Br-solution(# opt freq b3lyp/6-311++g(d,p) scrf=(cpcm,solvent=water,read))
Zero-point correction=                         0.000000 (Hartree/Particle)
Thermal correction to Energy=                   0.001416
Thermal correction to Enthalpy=                0.002360
Thermal correction to Gibbs Free Energy=       -0.016176
Sum of electronic and zero-point Energies=       -2574.344613
Sum of electronic and thermal Energies=          -2574.343197
Sum of electronic and thermal Enthalpies=          -2574.342253
Sum of electronic and thermal Free Energies=       -2574.360789

G_solv^0= -2574.360789 +2574.253971=-0.106818

OH-gas(# opt freq b3lyp/6-311++g(d,p))
Zero-point correction=                         0.008535 (Hartree/Particle)
Thermal correction to Energy=                   0.010896
Thermal correction to Enthalpy=                0.011840
Thermal correction to Gibbs Free Energy=       -0.007721
Sum of electronic and zero-point Energies=          -75.818913
Sum of electronic and thermal Energies=             -75.816552
Sum of electronic and thermal Enthalpies=          -75.815608
Sum of electronic and thermal Free Energies=       -75.835169

OH-solution (# opt freq b3lyp/6-311++g(d,p) scrf=(cpcm,solvent=water,read))
Zero-point correction=                         0.008337 (Hartree/Particle)
Thermal correction to Energy=                   0.010697
Thermal correction to Enthalpy=                0.011642
Thermal correction to Gibbs Free Energy=       -0.007924
Sum of electronic and zero-point Energies=          -75.956417
Sum of electronic and thermal Energies=             -75.954056
Sum of electronic and thermal Enthalpies=          -75.953112
Sum of electronic and thermal Free Energies=       -75.972678

G_solv^0=-75.972678+75.835169= -0.137509 au

∆G_gas^0=-2574.253971--75.835169--420.234030+76.454884+2993.891801
   =0.023515 au=14.7554 kcal•mol-1

∆G_gas^0 (1M)= ∆G_gas^0 (1 atm)+RTln24.46=16.5924 kcal•mol-1

∆G_solv^0= -0.137509-0.106818-0.199352+0.098886 au+6.3 kcal•mol-1
   =-216.3576+6.3=-210.0576 kcal•mol-1

∆G_aq^0=16.5924-210.0576=-193.4652 kcal•mol-1

E=-(-193.4652)/2/23.061=4.1946 V

请教大神，这样算错误出在哪里，跪求

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