Energy Units

	Hartree (2Ry)	eV	cm-1	kcal/mol	kJ/mol	Kelvin	J	Hz
Hartree	1	27.2107	219474.63	627.503	2625.5	315777.	43.60x10^-19	6.57966x10^+15
eV	0.0367502	1	8065.73	23.0609	96.4869	11604.9	1.60210x10^-19	2.41804x10^+14
cm^-1	4.55633x10^-6	1.23981x10^-4	1	0.00285911	0.0119627	1.42879	1.98630x10^-23	2.99793x10^+10
kcal/mol	0.00159362	0.0433634	349.757	1	4.18400	503.228	6.95x10^-21	1.04854x10^+13
kJ/mol	0.00038088	0.01036410	83.593	0.239001	1	120.274	1.66x10^-21	2.50607x10^+12
Kelvin	0.00000316678	0.0000861705	0.695028	0.00198717	0.00831435	1	1.38054x10^-23	2.08364x10^+10
J	2.294x10^+17	6.24181x10^+18	5.03445x10^+22	1.44x10^+20	6.02x10^+20	7.24354x10^+22	1	1.50930x10^+33
Hz	1.51983x10^-16	4.13558x10^-15	3.33565x10^-11	9.53702x10^-14	5.7×10^^-14	4.79930x10^-11	6.62561x10^-34	1

Pressure Units

	bar	mmHg	N/m2(pascal)	torr
bar	1	750.0615613	10^5	750.06167382
mmHg	0.0013332239	1	133.32239	1.00000015
pascal	10^-5	0.007500615613	1	0.0075006167382
torr	0.0013332237	0.99999984999	133.32237	1

普朗克常数 $6.62607015×10^{-34} m^2kg/s$
玻尔兹曼常数 $1.380649×10^{-23} m^2kg/s^{2}K^{1}$
阿伏伽德罗常数 $6.02214076×10^{23} /mol$
$1 cal = 4.184 J$
氢原子基态能量 $-13.6 eV = -1 Ry$
对于光子，$E=pc=h\widetilde{k}c$，其中$\widetilde{k}$是波数，单位$cm^{-1}$
对于光子，$E=h\nu$
对于声子，$E=kT$

from http://home.ustc.edu.cn/~lipai/tools/unit_convert.html