一些熱力學性質的計算統計熱力學頻率分析根本輸出講解反響焓的計算基于原子化反響計算生成焓的方法基于等鍵反響計算生成焓的方法統計熱力學

頻率分析根本輸出講解

計算其他溫度下的熱力學量：關鍵字中加Freq=ReadIsotopes且分子說明后添加如下內容：一些組合方法輸出結果分析金標準：CCSD〔T〕外推至完備基組〔CBS〕,計算稍大體系難以實現組合方法：Gn系列G1/G2/G3/G4CBS系列CBS-APNO/CBS-Q/CBS-4W1/W2/W3/W4精度極高

反響焓的計算

HF/STO-3GC2H5H2C2H6H-77.662991-1.117505-78.306179-0.4665810.0708190.0124870.0897020.0000000.0744850.0148480.0930540.0014160.0754290.0157920.0939980.0023600.0470370.0010790.068319-0.010654-77.592179-1.105019-78.216478-0.466582-77.588513-1.102658-78.213126-0.465166-77.587569-1.101714-78.212181-0.464221-77.615961-1.116427-78.237861-0.477236

反響速率的計算

L.A.Curtiss,J.Chem.Phys.,109(1998)7764基于原子化反響的方法

實驗值：-17.89kcal/mol

MP2/6-31g*CCSD/cc-pvtzB3LYP/6-31g*CBS-QB3W1G2實驗值ΔfH(C,0K)0.2708800.2708800.2708800.2708800.2708800.270880

ΔfH(H,0K)0.0822780.0822780.0822780.0822780.0822780.082278

ε(C)-37.680860-37.778726-37.846280-37.785377-37.852931-37.784301

ε(H)-0.498233-0.499809-0.500273-0.499818-0.499994-0.500000

ε(CH4)+εZPE(CH4)-40.286199-40.386741-40.473175-40.409999-40.479068-40.410891

H(CH4,298K)-H(CH4,0K)0.0038030.0038110.0038080.0038150.0038160.003816

H(C,298K)-H(C,0K)0.0003980.0003980.0003980.0003980.0003980.000398

H(H,298K)-H(H,0K)0.0016100.0016100.0016100.0016100.0016100.001610

ΔfH(CH4,0K)

Hartree-0.012416-0.008789-0.025813-0.025359-0.026170-0.026599

ΔfH(CH4,298K)

Hartree-0.015450-0.011815-0.028841-0.028381-0.029191-0.029620

ΔfH(CH4,298K)

kcal/mol-9.69-7.41-18.10-17.81-18.32-18.