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标题: 非键相互作用过大导致平衡模拟崩溃 [打印本页]

作者
Author:
1416339770    时间: 2023-1-30 21:51
标题: 非键相互作用过大导致平衡模拟崩溃
em.gro(己烷包裹水滴)与金板组合起来进行平衡,模拟崩溃显示如下(没有显示Fatal error):
WARNING: Listednonbonded interaction between particles 723371 and 723379
at distance 8.663which is larger than the table limit 2.048 nm.
This is likelyeither a 1,4 interaction, or a listed interaction inside
a smaller moleculeyou are decoupling during a free energy calculation.
Since interactionsat distances beyond the table cannot be computed,
they are skippeduntil they are inside the table limit again. You will
only see thismessage once, even if it occurs for several interactions.
IMPORTANT: Thisshould not happen in a stable simulation, so there is
probably somethingwrong with your system. Only change the table-extension
distance in the mdpfile if you are really sure that is the reason.
Step 0  Warning: pressure scaling more than 1%, mu:36506.7 36506.7 36506.7
step 0

初始结构(红色为金板(AU),蓝色为己烷,结构中间有两个水滴)和能量最小化后势能曲线如图所示。

除本例失败外,尝试过用共轭梯度法跑能量最小化、减少己烷分子数、调整己烷与金板距离、去掉冻结或控压,均报错。去掉金板,只留己烷和水,能正常平衡和md。请问本例模拟崩溃表明什么,大概率是什么原因,怎么解决,mdptop文件有错误吗

能量最小化文件em.mdp
define = -DFLEXIBLE
integrator = steep
nsteps = 1000000
emtol  = 100.0
emstep = 0.01
;
nstxout   = 100
nstlog    = 50
nstenergy = 50
;
pbc = xyz
cutoff-scheme            = Verlet
coulombtype              = PME
rcoulomb                 = 1.0
vdwtype                  = Cut-off
rvdw                     = 1.0
DispCorr                 = EnerPres
;
constraints              = none
平衡文件eq.mdp:
define =
integrator = md
dt         = 0.001
nsteps     = 300000
comm-mode  =
comm-grps  =
energygrps =
;
nstxout = 1000
nstvout = 1000
nstfout = 1000
nstlog  = 1000
nstenergy = 1000
nstxout-compressed =1000
compressed-x-grps  = system
;
tc_graps  = water _ICZ AU
annealing = singlesingle single
annealing_npoints =2 2 2
annealing_time = 0100 0 100 0 100
annealing_temp = 0298.15 0 298.15 0 298.15
;
pbc = xyz
cutoff-scheme =Verlet
coulombtype   = PME
rcoulomb      = 1.0
vdwtype       = cut-off
rvdw          = 1.0
DispCorr      = EnerPres
;
Tcoupl  = V-rescale
tau_t   = 0.2 0.2 0.2
tc_grps = water _ICZAU
ref_t   = 298.15 298.15 298.15
;
Pcoupl     = Berendsen
pcoupltype =isotropic
tau_p = 2.0
ref_p = 1.0
compressibility =4.5e-5
;
gen_vel  = no
gen_temp = 298.15
gen_seed = -1
;
freezegrps  = top bottom
freezedim   = N Y N N Y N
constraints = none
拓扑文件如下:
#include"gromos54a7_atb.ff/forcefield.itp"
#include"gromos54a7_atb.ff/spce.itp"
#include"C6H14.itp"
[ system ]
AUW
[ moleculetype ]
; molname   nrexcl
AU         1
[ atoms ]
; id    at type res nr  residu name at name  cg nr charge   mass
1       AU   1       AU         AU       1     0.0        196.9665
[ molecules ]
SOL         7500
_ICZ        60000

AU          115248


作者
Author:
sobereva    时间: 2023-1-30 23:40
排查办法无外乎就这些:http://sobereva.com/soft/Sobtop#FAQ8

大概率是拓扑文件的问题。
另外这种体系不适合用enerpres。这个体系也明显不适合用各项同性控压
作者
Author:
1416339770    时间: 2023-1-31 13:00
sobereva 发表于 2023-1-30 23:40
排查办法无外乎就这些:http://sobereva.com/soft/Sobtop#FAQ8

大概率是拓扑文件的问题。

好的,谢谢sob老师指点




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