| 查看: 757 | 回复: 0 | |||
[交流]
【求助】Ni的声子计算
|
|
我想计算Ni的声子谱。 第一步，先做了结构优化计算，输入文件如下： # Ni fcc structure with two atoms per unit cell #Ni is a ferromagnatic material #spin definition nsppol 2 nspden 2 spinat 0.0 0.0 4.0 prtdos 1 prtden 1 #Structure optimize optcell 1 ionmov 2 ntime 15 dilatmx 1.05 tolmxf 1.0e-6 ecutsm 0.5 ####################################################### #Common data acell 3*6.65184 rprim 0.0 0.5 0.5 0.5 0.0 0.5 0.5 0.5 0.0 ntypat 1 znucl 28 natom 1 typat 1 xred 0.0 0.0 0.0 ixc 11 occopt 3 tsmear 0.01 nband 10 kptopt 1 ngkpt 8 8 8 nshiftk 4 shiftk 0.5 0.5 0.5 0.5 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.5 ecut 60.0 tolvrs 1.0d-18 iscf 5 nstep 70 diemac 12 计算得到的结果是：acell=6.73,查阅文献的结果是：6.65. 下面计算声子， 第一步，先做了，GS 计算,输入文件是： # Ni fcc structure with two atoms per unit cell #Ni is a ferromagnatic material #spin definition nsppol 2 nspden 2 spinat 0.0 0.0 4.0 prtdos 1 prtden 1 #Structure optimize #optcell 1 #ionmov 2 #ntime 15 #dilatmx 1.05 #tolmxf 1.0e-6 ecutsm 0.5 ####################################################### #Common data acell 3*6.65 rprim 0.0 0.5 0.5 0.5 0.0 0.5 0.5 0.5 0.0 ntypat 1 znucl 28 natom 1 typat 1 xred 0.0 0.0 0.0 ixc 11 occopt 3 tsmear 0.01 nband 10 kptopt 1 ngkpt 8 8 8 nshiftk 4 shiftk 0.5 0.5 0.5 0.5 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.5 ecut 50 tolvrs 1.0d-18 iscf 5 nstep 70 diemac 12 计算得到WFK文件，以上两步计算都没有问题，no warning and no comment. 第二步计算Gamma点的声子。 输入文件如下， # Crystalline Ni : computation of the second drivative of the total energy # #Ni is a ferromagnatic material #spin definition nsppol 2 nspden 2 spinat 0.0 0.0 4.0 #Response-function calculatio, with q=0 rfphon 1 # Will consider phonon-type perturbation rfatpol 1 1 # all the atoms wiil be displaced rfdir 1 1 1 # Along the first reduced coordinate axis nqpt 1 # One wavevector is to be considered qpt 0 0 0 # This wavevector is q=0 (Gamma) kptopt 2 # Automatic generation of k points, taking # into account the time-reversal symmetry only tolvrs 1.0d-8 # SCF stopping criterion iscf 5 # Self-consistent calculation, using algorithm 5 irdwfk 1 # Read the ground-state wavefunctions ######################################################################### #common input variables #Definition of the unit cell acell 3*6.65 rprim 0.0 0.5 0.5 # In lessons 1 and 2, these primitive vectors 0.5 0.0 0.5 # (to be scaled by acell) were 1 0 0 0 1 0 0 0 1 0.5 0.5 0.0 # that is, the default. #Definition of the atom types ntypat 1 # There is only one type of atom znucl 28 # The keyword "znucl" refers to the atomic number of the # possible type(s) of atom. The pseudopotential(s) # mentioned in the "files" file must correspond # to the type(s) of atom. Here, the only type is Silicon. #Definition of the atoms natom 1 # There are two atoms typat 1 # They both are of type 1, that is, Silicon. xred # This keyword indicate that the location of the atoms # will follow, one triplet of number for each atom 0.0 0.0 0.0 # Triplet giving the REDUCED coordinate of atom 1. # Triplet giving the REDUCED coordinate of atom 2. # Note the use of fractions (remember the limited # interpreter capabilities of ABINIT) #Definition of the planewave basis set ecut 50.0 # Maximal kinetic energy cut-off, in Hartree #Definition of the k-point grid ngkpt 8 8 8 # This is a 8x8x8 grid based on the primitive vectors nshiftk 4 # of the reciprocal space (that form a BCC lattice !), # repeated four times, with different shifts : shiftk 0.5 0.5 0.5 0.5 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.5 # In cartesian coordinates, this grid is simple cubic, and # actually corresponds to the # so-called 4x4x4 Monkhorst-Pack grid ixc 11 occopt 3 tsmear 0.05 nband 10 #Definition of the SCF procedure nstep 80 # Maximal number of SCF cycles diemac 12.0 # Although this is not mandatory, it is worth to # precondition the SCF cycle. The model dielectric # function used as the standard preconditioner # is described in the "dielng" input variable section. # Here, we follow the prescription for bulk silicon. 问题就来了，得不到合理的结果， 而且log中有一大堆这样的WARNING: cgwf3.F90:701:WARNING New trial energy at line 4 = -8.174248E+02 is higher than former: -8.174248E+02 得到Gamma点声子竟然为： Phonon wavevector (reduced coordinates) : 0.00000 0.00000 0.00000 Phonon energies in Hartree : -3.212615E-03 -3.212615E-03 -3.212615E-03 Phonon frequencies in cm-1 : - -7.050876E+02 -7.050876E+02 -7.050876E+02 有哪位达人能够帮我啊？告诉我问题出在哪里？ 计算中所使用的赝势，可以在这里下载： http://www.sas.upenn.edu/rappegroup/htd ... p_gga.html |
回复此楼» 猜你喜欢
本人考085602 化学工程 专硕
已经有9人回复
-
材料与化工一志愿南昌大学327求调剂推荐
已经有7人回复
-
326求调剂
已经有3人回复
-
焦虑
已经有8人回复
-
308求调剂
已经有4人回复
-
NSFC申报书里申请人简历中代表性论著还需要在申报书最后的附件里面再上传一遍吗
已经有14人回复
-
化学调剂0703
已经有7人回复
-
327求调剂
已经有11人回复
-
调剂
已经有8人回复
-
梁成伟老师课题组欢迎你的加入
已经有7人回复
找到一些相关的精华帖子，希望有用哦~
今天用CASTEP计算声子谱，出现下列提示，有能看懂的大侠帮忙解释下
已经有11人回复
- 为何用晶格常数的实验值计算声子？
已经有18人回复
- 关于用超胞方法计算声子的一些经验
已经有21人回复
- Abinit计算声子问题
已经有10人回复
- ZnO的声子计算
已经有18人回复
- 声子计算又负频的出现！！！
已经有24人回复
- MS计算晶体声子谱的时候，横坐标有负能量值，为什么？
已经有11人回复
- castep计算Fe2O3声子谱失败，原因求教~~
已经有10人回复
- 自旋体系的声子计算应该用什么软件呢？
已经有5人回复
- 【求助】castep计算声子谱，为什么不能进行振动分析
已经有9人回复
- 【求助】使用vasp进行带心冻结声子计算的几个问题~~~
已经有9人回复
- 【求助】请教CASTEP计算声子谱后出现虚频
已经有6人回复
- 【求助】有人用有限差分方法计算过G点声子谱吗？
已经有10人回复
- 【求助】请问大家在做声子计算时，这个 qpt是按照什么设置的？？？？
已经有9人回复
- 【求助】用MS中的castep计算声子振动模频率，具体怎么算
已经有10人回复
点击这里搜索更多相关资源科研从小木虫开始，人人为我，我为人人
