24小时热门版块排行榜    

查看: 1177  |  回复: 18
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

yq2240711

金虫 (正式写手)

[交流] 【求助】如何从算出的E-a数值拟和出晶格常数a0

如何从算出的一系列E-a数值拟和出晶格常数a0
如何利用物态方程拟和晶格常数?

[ Last edited by yq2240711 on 2009-11-21 at 21:19 ]
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xirainbow

木虫 (正式写手)

引用回帖:
Originally posted by zdd2008 at 2009-11-11 22:15:
建议拟合时不要使用普通的多项式进行拟合!

当然如果你只为了得到平衡体积(平衡晶格常数)和对应的能量,你可以使用多项式拟合!

但使用多项式拟合没有物理意义,因此,建议使用物态方程拟合!这样拟合不仅 ...

请问,如何使用物态方程拟合正交,单斜,三斜晶系的情况呢:)?

[ Last edited by xirainbow on 2009-11-11 at 22:38 ]
7楼2009-11-11 22:35:32
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 19 个回答

xirainbow

木虫 (正式写手)

★ ★ ★ ★
yq2240711(金币+3,VIP+0): 11-11 19:35
yjmaxpayne(金币+1,VIP+0):谢谢解答 11-11 20:01
用pwscf可以直接拟合,参看:
http://blog.sina.com.cn/s/blog_5f15ead20100f5jx.html

可以直接用泰勒展开去拟合么?
请高人帮忙;)
2楼2009-11-11 19:34:39
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

zdhlover

荣誉版主 (职业作家)

小木虫之莲花佛

★ ★ ★ ★ ★ ★
yq2240711(金币+1,VIP+0): 11-11 20:40
yjmaxpayne(金币+5,VIP+0):非常感谢提供信息 11-11 21:17
On the other hand, we may use a relatively simple approach to refine the determined equilibrium
value of the lattice constant by fitting our sampled data points to a second order
polynomial of the form

P(a)=A(a-a0)*(a-a0)+B(a-a0)+c
We may then choose the minimum of P(a)
amin=a0-B/(2A)
as the value of the lattice constant . We now set a0=2.999 (the central point of the interval) and let h= 0.01 Rydberg (the equidistant spacing between sample points). In addition, using a few algebraic manipulations leads to the following analytic expressions for the two constants A and B
:

A=(E(a0+h)+E(a0-h)-2E(a0))/(2h*2h)
and
B=(E(a0+h)-E(a0-h)))/2h

then you can get the lattice constant :amin=a0-B/(2A)
3楼2009-11-11 20:06:57
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xirainbow

木虫 (正式写手)

引用回帖:
Originally posted by zdhlover at 2009-11-11 20:06:
On the other hand, we may use a relatively simple approach to refine the determined equilibrium
value of the lattice constant by fitting our sampled data points to a second order
polynomial of th ...

您提供的信息太好了:)
请问,您从哪里获得的这些说明 ?
能给个链接么?
谢谢啦;)
4楼2009-11-11 20:54:09
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
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
[博后之家] 售SCI一区文章,我:8.O.55.1.O.54,科目齐全,可伽急 +3 SX5mJmPWDfOO 2026-11-13 3/150 2026-11-15 08:40 by xSrQNSSjcgoX
[硕博家园] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +3 XJXMuRjD7cK7 2026-11-13 3/150 2026-11-15 05:22 by xSrQNSSjcgoX
[文学芳草园] 厉娜 +4 张丹枫1991 2026-11-09 6/300 2026-11-15 00:48 by Equinoxhua
[硕博家园] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +7 0TEMgxdT1eIw 2026-11-09 10/500 2026-11-15 00:39 by Equinoxhua
[硕博家园] 售SCI文章,我:8O5.5.1.O.54,科目齐全,可+急 +4 G2rhSvqvhNzl 2026-11-10 6/300 2026-11-15 00:27 by Equinoxhua
[考研] 售SCI一区T0P文章,我:8.O.55.1.O.54,科目齐全,可+急 +4 YHiw1gou1Eda 2026-11-10 7/350 2026-11-14 22:44 by Equinoxhua
[硕博家园] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +5 YHiw1gou1Eda 2026-11-10 8/400 2026-11-14 22:20 by Equinoxhua
[论文投稿] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +4 gRND4NVAZ8VG 2026-11-11 5/250 2026-11-13 11:15 by Equinoxhua
[考研] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +5 C6CRn66RYYXS 2026-11-10 6/300 2026-11-13 11:04 by Equinoxhua
[论文投稿] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +3 TgvkbZZl9tqB 2026-11-11 4/200 2026-11-12 12:51 by ECLTXnJnRSXf
[基金申请] 售SCI-T0P文章,我:8O.5.5.1.O.54,科目齐全,可+急 +4 Z7qfCsdIiD1T 2026-11-10 7/350 2026-11-12 11:33 by HajghKOMynmz
[公派出国] 售SCI一区T0P文章,我:8.O.55.1.O.54,科目齐全,可+急 +3 Z7qfCsdIiD1T 2026-11-10 7/350 2026-11-12 11:31 by HajghKOMynmz
[硕博家园] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +4 Z7qfCsdIiD1T 2026-11-10 6/300 2026-11-12 11:22 by HajghKOMynmz
[教师之家] 售SCI-T0P文章,我:8O.5.5.1.O.54,科目齐全,可+急 +4 czAiolzR0IJC 2026-11-10 7/350 2026-11-12 11:00 by HajghKOMynmz
[考博] 售SCI一区T0P文章,我:8.O.55.1.O.54,科目齐全,可+急 +3 G2rhSvqvhNzl 2026-11-10 5/250 2026-11-12 10:49 by HajghKOMynmz
[考博] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +4 C6CRn66RYYXS 2026-11-10 6/300 2026-11-12 10:27 by HajghKOMynmz
[硕博家园] 售SCI一区文章,我:8.O.55.1.O.54,科目齐全,可伽急 +4 C6CRn66RYYXS 2026-11-10 6/300 2026-11-12 10:16 by HajghKOMynmz
[考博] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +5 FChKX8meu1ds 2026-11-09 8/400 2026-11-12 09:46 by HajghKOMynmz
[考研] 售SCI一区文章,我:8O5.5.1.O5.4,科目全,可伽急 +8 cqv1zKnzd7hr 2026-11-09 12/600 2026-11-12 09:32 by HajghKOMynmz
[考博] 售SCI一区T0P文章,我:8.O.55.1.O.54,科目齐全,可+急 +3 FChKX8meu1ds 2026-11-09 8/400 2026-11-12 05:30 by 9fOTqj074tIg
信息提示
请填处理意见