Calculations were carried out using DFT Perdew–Wang 1991 (PW91)  exchange-correlation functional implemented in the plane-wave based code VASP . The electron–core interaction is described with the projector-augmented plane-wave (PAW) method. A plane-wave basis set with a kinetic energy cutoff of 400 eV was used. Test calculations on water adsorption at Cu(1 1 1) surface with a 500 eV cutoff produced the same adsorption energy and the almost unchanged geometry of water (Only the bond angle HOH differs by 0.2°.). Convergence criteria of 10E-5 eV for the self-consistent electronic minimization and 10E-4 eV for the total energy change between two consecutive ionic steps were adopted.
…………
A Monkhorst–Pack mesh [60] of (5 · 5 · 1) was used for integration over the Brillouin zone for the (1 1 1), (1 0 0), (1 1 0) and (2 1 1) surfaces.

System = Cu(100)-surface H2O
PREC = Normal
EDIFF = 1E-5
EDIFFG = 1E-3
GGA = 91
ISPIN = 1
ICHARG = 2
ISTART = 0
ENCUT =  720
SIGMA =  0.2
ISMEAR = 1
NELMDL = -12        #
ALGO = Fast         #RMM-DIIS
ISIF = 2
IBRION = 1          #for:ZBRENT: increasing intervall
ADDGRID = .True.    #
NSW = 360           #try to increase it when cannot converage

LORBIT = 11
LREAL = Auto        #for large cell, if cell small,then set to .FALSE.
NCORE = 12          #for linux multicores, cores used per node
LPLANE = .TRUE.     #if very nodes used,then set to .FALSE.
LSCALU = .FALSE.
NSIM = 4
LWAVE = .FALSE.            #will not creat the wavecar
LCHARG = .FALSE.        #will not creat the chagcar

System = Cu(100)-surface H2O
PREC = ACCURATE
EDIFF = 1E-6
EDIFFG = 1E-4
GGA = 91
ISPIN = 1
ICHARG = 2
ISTART = 0
ENCUT =  700
SIGMA =  0.2
ISMEAR = -5
NELMDL = -12        #
ADDGRID = .True.
IBRION = 1
ALGO = Fast         #RMM-DIIS

LORBIT = 11
LREAL = Auto        #for large cell, if cell small,then set to .FALSE.
NCORE = 12          #for linux multicores, cores used per node
LPLANE = .TRUE.     #if very nodes used,then set to .FALSE.
LSCALU = .FALSE.
NSIM = 4
LWAVE = .FALSE.            #will not creat the wavecar
LCHARG = .FALSE.        #will not creat the chagcar

2楼: Originally posted by hakuna at 2012-10-18 00:04:20
你的INCAR里有些参数彼时必须的，譬如ISPIN、LORBIT.......
你的截断能太高了，浪费时间，那篇文章截断能最多400 eV.....
另外，注意一下你水分子的能量是怎么算的，是否放在一个大盒子里，取gama点计算得到..... ...

top           0.160811
center      0.126289
bridge      0.167322

2楼: Originally posted by hakuna at 2012-10-18 00:04:20
你的INCAR里有些参数彼时必须的，譬如ISPIN、LORBIT.......
你的截断能太高了，浪费时间，那篇文章截断能最多400 eV.....
另外，注意一下你水分子的能量是怎么算的，是否放在一个大盒子里，取gama点计算得到..... ...

System = Cu(100)-H2O
PREC = Accurate
EDIFF = 1E-5
EDIFFG = 1E-4
GGA = 91
ISPIN = 1
ICHARG = 2
ISTART = 0
ENCUT =  420
SIGMA =  0.1
ISMEAR = 1
NELMDL = -12        #
ALGO = Fast         #RMM-DIIS
ISIF = 2
IBRION = 1          #for:ZBRENT: increasing intervall
ADDGRID = .True.    #
NSW = 120           #

LORBIT = 11
LREAL = Auto        #for large cell, if cell small,then set to .FALSE.
NCORE = 12          #for linux multicores, cores used per node
LPLANE = .TRUE.     #if very nodes used,then set to .FALSE.
LSCALU = .FALSE.
NSIM = 4
LWAVE = .FALSE.            #will not creat the wavecar
LCHARG = .FALSE.        #will not creat the chagcar

System = Cu(100)-surface H2O
PREC = ACCURATE
EDIFF = 1E-6
EDIFFG = 1E-4
GGA = 91
ISPIN = 1
ICHARG = 2
ISTART = 0
ENCUT =  420
SIGMA =  0.1
ISMEAR = -5
NELMDL = -12        #
ADDGRID = .True.
IBRION = 1
ALGO = Fast         #RMM-DIIS

LORBIT = 11
LREAL = Auto        #for large cell, if cell small,then set to .FALSE.
NCORE = 12          #for linux multicores, cores used per node
LPLANE = .TRUE.     #if very nodes used,then set to .FALSE.
LSCALU = .FALSE.
NSIM = 4
LWAVE = .FALSE.            #will not creat the wavecar
LCHARG = .FALSE.        #will not creat the chagcar

5楼: Originally posted by dazao at 2012-10-24 05:46:52
文献里媳吸附能的单位是焦耳每木耳吧

我i做过水在U表面吸附，分子吸附时HOH贱角105左右，和自由水分子的差不多

7楼: Originally posted by gleerat at 2012-10-25 10:27:30
文献的能量值是KJ/mol，约等于0.01eV。
水分子在Cu表面的吸附不强，分子构型基本上与自由水分子差不多。...

6楼: Originally posted by gleerat at 2012-10-25 10:22:09
截断能是太高了，但是不至于影响结果吧。
其实，我再次优化出来的Cu(100)表面上top位模型中，结构与文献报道差不多，二面角98度，d(CuO)为2.33，吸附能为0.19eV。符合的还比较好。
但是对于bridge和center位吸附 ...

8楼: Originally posted by hakuna at 2012-10-25 15:34:41
"文献的能量值是KJ/mol，约等于0.01eV。"

换算错了吧...