QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Timbaktoo on September 3, 2009, 09:27

Title: Reg. Geometric optimization in VNL
Post by: Timbaktoo on September 3, 2009, 09:27

Hi all,

I am curious to know how do I do geometric-relaxation for bulk when using VNL? Thing is that when I prepare the bulk structure and drop it on the nano-scripter, I can set the geometric-optimization method(either Quasi-newton or steepest-decline) and its relevant parameters. But when I start running the script, the first few lines in the job-manager window that shows the co-ordinates are not different from my initial co-ordinates. I would expect them to be different if the relaxation has taken place in the structure.

Thanks.

Title: Re: Reg. Geometric optimization in VNL
Post by: zh on September 3, 2009, 09:41

Please note that the atomic coordinates printed in the first few lines of the log file are given in the Cartesian coordination. Maybe, in your nanolanguage script file they are given in fractional coordination.

Title: Re: Reg. Geometric optimization in VNL
Post by: Timbaktoo on September 3, 2009, 10:16

Thanks for the reply, zh.

I guess there is some confusion. So, I have both the co-ordinates in cartisan form (bulk-builder has option of showing the co-ordinates in both fractional as well as cartisan format). So, the cartisan-coordinates in my script file 'are matching' with those in the log-file. Since, I selected quasi-newton in the VNL, these should NOT match.

So, could you please re-iterate how do we do the geometrical-optimization using VNL. I mean, do I need to change something in the script-file also, although I have initially selected the method in VNL???

Thanks.

Title: Re: Reg. Geometric optimization in VNL
Post by: zh on September 4, 2009, 07:24

Quote from: Timbaktoo on September  3, 2009, 10:16

So, could you please re-iterate how do we do the geometrical-optimization using VNL. I mean, do I need to change something in the script-file also, although I have initially selected the method in VNL???

Since the setup for geometry optimization can be specified in VNL using mouse to choose the optimization method and relevant parameters,  usually it is no necessary to edit the script file to change the setup for geometry optimization.

Recommend you to execute your script file in the following manner, rather that dragging them onto the "Job Manager":
atk  your_script_file

In my test cases using the atk command, I did not meet the problem you have reported.