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标题: 求助：能量最小化步骤无法收敛 [打印本页]

作者
Author: suxiao 时间: 2021-8-18 11:48
标题: 求助：能量最小化步骤无法收敛
体系是离子液体、药物和水三元体系，采用的是steep 算法 (, 下载次数 Times of downloads: 3) ; LINES STARTING WITH ';' ARE COMMENTS
title = Minimization ; Title of run

; Parameters describing what to do, when to stop and what to save
integrator = steep ; Algorithm (steep = steepest descent minimization)
emtol = 100.0    ; Stop minimization when the maximum force < 10.0 kJ/mol
emstep = 0.01    ; Energy step size
nsteps = 50000       ; Maximum number of (minimization) steps to perform

; output frequency
nstxout = 10
nstvout = 0
nstfout = 0
nstlog = 50
nstenergy = 50
nstxtcout = 0
xtc_grps = system

; Parameters describing how to find the neighbors of each atom and how to calculate the interactions
nstlist = 10       ; Frequency to update the neighbor list and long range forces
pbc = xyz ; Periodic Boundary Conditions
cutoff-scheme = Verlet
ns_type = grid ; Method to determine neighbor list (simple, grid)
rlist = 1.2 ; Cut-off for making neighbor list (short range forces)
coulombtype = PME ; Treatment of long range electrostatic interactions
rcoulomb = 1.2 ; long range electrostatic cut-off
vdwtype       = cut-off
rvdw = 1.2 ; long range Van der Waals cut-off
DispCorr       = EnerPres
;
constraints = none
constraint_algorithm = LINCS
implicit_solvent = no

报错信息如下所示：
(, 下载次数 Times of downloads: 10)

已经尝试过更改为cg算法，更改静电和范德华作用方法和截断距离，仍然无法正常收敛

也更改过初始构型和拓扑文件，重新构建初始结构，依然无法收敛至100KJ／mol.

请问可能的原因是什么呢?还能用什么方法尝试呢?

以下为拓扑文件 (, 下载次数 Times of downloads: 3) (, 下载次数 Times of downloads: 0) (, 下载次数 Times of downloads: 2) (, 下载次数 Times of downloads: 0)

作者
Author: sobereva 时间: 2021-8-18 22:45
不提供具体结构谁也没法准确判断

如果做em的目的只是之后MD能跑起来，没必要收敛到100KJ／mol这么严

mdp没明显问题。出现这种报错要么拓扑文件有问题，要么初始结构存在硬伤。

最好把体系尽可能简化，反复对比尝试找原因，别一下子就搞三元的。

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