应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

小木虫论坛-学术科研互动平台 » 计算模拟区 » 分子模拟 » Gromacs/Amber/NAMD » 【求助】建配体的力场，大家都用什么方法计算电荷？
北京石油化工学院2026年研究生招生接收调剂公告
51/1返回列表
查看: 1146  |  回复: 3
只看楼主 @他人 存档 新回复提醒 (忽略) 收藏    在APP中查看
当前主题已经存档。
当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

楼1970-01-01 08:00:00
已阅   申请模拟EPI   回复此楼   编辑   查看我的主页

bay__gulf

金虫 (著名写手)

刘苏州
★ ★ ★ ★
小木虫(金币+0.5):给个红包，谢谢回帖交流
lei0736(金币+3):谢谢 2010-04-14 15:56
力场中的电荷并非原子真实的电荷, 而是根据某一计算方法得出的数值
放到整个力场参数中进行拟合得到的. 不同力场计算电荷的方法不同, 数值差别也很大
比如charmm 使用hf/6-31g* 基组下的Mullikin 电荷, 而amber 用的则是ESP.

Methodologies for Developing the Partial Charges

Now is a good time to discuss the determination of the partial charges appearing
in the topology file. Two widely used force fields are CHARMM and AMBER
– and they both use di?erent protocols to develop the partial atomic charges.

CHARMM starts with the Mullikin charges and then strategically places a
water molecule near any polar group. CHARMM’s charges are refined so that
they best reproduce the interaction energy between the water and the polar
group. To recreate these values, the partial charges of the polar group are then
altered until this interaction energy is accurately replicated with the MD sim-
ulations. Several concrete examples of this charge-fitting strategy are worked
out in Ref. [7].

AMBER, on the other hand, begins with the ESP charges and then uses a
program they distribute called RESP (for Restricted ESP). This charge-fitting
scheme replicates the electrostatic potential at a distance out from the nucleus
(much like the surface you built in the previous exercise) with only the atom
centers having charge. Of course, the electrostatic surface generated using this
methodisoftendegenerate; meaningtherecouldbemorethanonesetofcharges
that would reproduce the potential surface. To resolve this issue, it is best to
further restrict your potential surface by supplying it an initial set of charges for
the program’s iterations, or further restrictions derived from chemical insight

However they are generated, the importance of a good set of partial charges
cannot be overstated. Much of the energy (and indirectly then, the behavior)
of the system will be calculated using these values.
赞一下(3人) 回复此楼
3楼2010-04-14 15:30:37
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 4 个回答

zyj8119

木虫 (著名写手)
★ ★
小木虫(金币+0.5):给个红包，谢谢回帖交流
lei0736(金币+1):谢谢 2010-04-14 15:22
在GAUSSIAN里面使用CHELPG
赞一下(3人) 回复此楼
好好学习，天天向上。
2楼2010-04-14 15:17:37
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

vallen

银虫 (正式写手)
我看很多文章里都用resp方法得到电荷，这个方法有什么优点吗？
amber的例子里有用am1-bcc方法的，这个方法怎么样呢？
赞一下 回复此楼
4楼2010-04-16 16:02:48
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 4 个回答
普通表情 龙 兔 虎 猫 高级回复 (可上传附件)
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 085600，材料与化工321分求调剂 +5 大馋小子 2026-03-28 5/250 2026-03-28 12:48 by 果果妈咪
[考研] 数一英一271专硕（085401）求调剂，可跨 +4 前行必有光 2026-03-28 5/250 2026-03-28 11:27 by xuxiang
[考研] 329求调剂 +5 星野? 2026-03-26 5/250 2026-03-28 08:17 by Iveryant
[考研] 291求调剂 +7 孅華 2026-03-22 7/350 2026-03-28 04:02 by fmesaito
[考研] 086000调剂 +3 7901117076 2026-03-26 3/150 2026-03-27 21:34 by Jianing_Mi
[有机交流] 高温高压反应求助 10+4 chibby 2026-03-25 4/200 2026-03-27 21:08 by BT20230424
[考研] 283求调剂（080500） +4 A child 2026-03-27 4/200 2026-03-27 15:34 by XPU李庆
[考研] 269专硕求调剂 +10 金恩贝 2026-03-21 10/500 2026-03-27 15:10 by caszguilin
[考研] 308求调剂 +7 墨墨漠 2026-03-25 7/350 2026-03-27 14:47 by 狂炫麦当当
[考研] 348求调剂 +4 小懒虫不懒了 2026-03-27 5/250 2026-03-27 12:47 by 果果妈咪
[考研] 299求调剂 +6 嗯嗯嗯嗯2 2026-03-27 6/300 2026-03-27 12:43 by 果果妈咪
[考研] 22408 359分调剂 +3 Qshers 2026-03-27 3/150 2026-03-27 12:22 by wxiongid
[考研] 303求调剂 +7 安忆灵 2026-03-22 8/400 2026-03-27 11:46 by sanrepian
[考研] 342求调剂 +3 加油a李zs 2026-03-26 3/150 2026-03-27 00:29 by wxiongid
[考研] 333求调剂 +6 wfh030413@ 2026-03-23 6/300 2026-03-26 22:45 by 学员8dgXkO
[考研] 263求调剂 +6 yqdszhdap－ 2026-03-22 10/500 2026-03-26 13:11 by 公瑾逍遥
[考研] 292求调剂 +4 鹅鹅鹅额额额额� 2026-03-24 4/200 2026-03-24 16:41 by peike
[考研] 材料/农业专业，07/08开头均可，过线就行 +3 呵唔哦豁 2026-03-23 4/200 2026-03-23 22:30 by 汪！？！
[考研] 306求调剂 +5 来好运来来来 2026-03-22 5/250 2026-03-22 16:17 by BruceLiu320
[考研] 一志愿南大，0703化学，分数336，求调剂 +3 收到VS 2026-03-21 3/150 2026-03-21 18:42 by 学员8dgXkO
信息提示
关闭
请填处理意见
关闭