Dear Jonas, I always use the foramt following to do a constrained geometry optimization. %block Zmatrix cartesian 4 0.832500 1.441900 0.070000 0 0 0 4 0.832500 4.325700 0.070000 0 0 0 4 0.832500 7.209500 0.070000 0 0 0 4 3.329900 0.000000 0.070000 0 0 0 4 3.329900 2.883800 0.070000 0 0 0 4 3.329900 5.767600 0.070000 0 0 0 4 5.827400 -1.441900 0.070000 0 0 0 4 5.827400 1.441900 0.070000 0 0 0 4 5.827400 4.325700 0.070000 0 0 0 1 3.602290 1.731278 6.212320 1 1 1 1 3.319832 2.314888 7.483680 1 1 1 1 2.095981 1.995008 8.160953 1 1 1 1 1.179880 1.055287 7.579063 1 1 1 1 1.463109 0.470284 6.307043 1 1 1 1 2.686364 0.792157 5.629784 1 1 1 2 4.560824 2.006388 5.644557 1 1 1 2 4.060912 3.044923 7.962504 1 1 1 2 0.218799 0.778868 8.141618 1 1 1 2 0.720051 -0.260182 5.831012 1 1 1 2 2.264637 3.524194 9.544223 1 1 1 2 0.774280 2.665518 9.602215 1 1 1 2 4.021096 0.084236 4.221899 1 1 1 2 2.491712 -0.710195 4.216641 1 1 1 3 1.840356 2.531978 9.498710 0 0 1 3 2.958183 0.262423 4.292613 0 0 1 4 2.438337 1.576108 2.385995 0 0 1 4 2.578104 1.329674 11.405459 0 0 1 4 1.665000 0.000000 13.722500 0 0 0 4 1.665000 2.883800 13.722500 0 0 0 4 1.665000 5.767600 13.722500 0 0 0 4 4.162400 -1.441900 13.722500 0 0 0 4 4.162400 1.441900 13.722500 0 0 0 4 4.162400 4.325700 13.722500 0 0 0 4 6.659800 -2.883800 13.722500 0 0 0 4 6.659800 0.000000 13.722500 0 0 0 4 6.659800 2.883800 13.722500 0 0 0 %endblock Zmatrix
in which 0 implies constraining,and 1 implies unconstraining. You can find it at pages 33-34 in siesta-3.0-b manual. Hope it to be helpful. 2010-04-28 Guangping Zhang 发件人: Jonas Baltrusaitis <jasiu...@yahoo.com> 发送时间: 2010-04-27 22:51 主 题: [SIESTA-L] constraints do not constrain 收件人: siesta-l@uam.es Dear all, after trying several times I have to conclude that geometry constraints in Siesta do not work. In the attached output (and several others) I tried to constraint bulk SiO2 in atomic position while relaxing only OH groups. To my surprise, all of the atoms moved, though inner, constrained atoms, somewhat less. Still, I was thinking that constrained atom position should not change at all. Does constraint work differently in Siesta and it allows those atom to relax? Jonas
