New features

[RMeli]

After discussing with @peterbygrave new features will be integrated to IRC. The changes are the following:

• Additional coordinate systems
  • DLC
  • HDLC
  • TRIC
• Additional initial Hessian model(s)
• Constraints

This issue is to track the integration, which will likely involve a refactoring of the library to change name (see Issue #15). There is no precise timeline for this, but priority will be given to additional coordinate systems.

[RMeli]

TRIC: Wang, L.-P.; Song, C.C., J. Chem, Phys. 144, 214108 (2016).

Implementation on GitHub: GeomeTRIC

[RMeli]

RIC: C. Y. Peng, P. Y. Ayala, H. B. Schlegel, and M. J. Frisch, J. Comput. Chem.17, 49 (1995).

[RMeli]

DLC: J. Baker, A. Kessi, and B. Delley, J. Chem. Phys.105, 192 (1996).

[RMeli]

ERIC: V. Bakken and T. Helgaker, J. Chem. Phys. 117, 9160 (2002).

@peterbygrave Extra-Redundant Internal Coordinates are the coordinates I was mentioning earlier.

[RMeli]

HDLC: S. R. Billeter, A. J. Turner and W. Thiel, Phys. Chem. Chem. Phys., 2, 2177-2186 (2000).

[AlexB67]

After discussing with @peterbygrave new features will be integrated to IRC. The changes are the following:

* [ ]  Additional coordinate systems
  
  * [ ]  DLC
  * [ ]  HDLC
  * [ ]  TRIC

* [ ]  Additional initial Hessian model(s)

* [ ]  Constraints

This issue is to track the integration, which will likely involve a refactoring of the library to change name (see Issue #15). There is no precise timeline for this, but priority will be given to additional coordinate systems.

Hello, thanks for the great software. If you wish I have code for the SCHLEGEL Hessian , it would be easy enough to incorporate I suppose .

I have a few questions if I may.

1. Out of plane bends are missing in your current simple guess Hessian, is that supposed to be or am I missing something I should know?
2. Are constraints actually working before I start delving deeper, I can't seem to be able to and given your comment as a issue to address I am now asking.

Thanks in advance.

[RMeli]

Hi @AlexB67, thank you for your interest in the library.

If you wish I have code for the SCHLEGEL Hessian , it would be easy enough to incorporate I suppose .

I've not been using or developing the library in a long time, so as this issue testifies it is not feature-complete by any stretch. However, I'm happy to consider new additions and of course bug fixes.

Out of plane bends are missing in your current simple guess Hessian, is that supposed to be or am I missing something I should know?

Out-of-plane bends have been added in #36 . The fact that they are missing from the simple guess of the Hessian looks like an oversight to me; unfortunately the IRC class is probably not as well tested as it should be.

Are constraints actually working before I start delving deeper, I can't seem to be able to and given your comment as a issue to address I am now asking.

IIRC we started implementing user-defined constraints, but the implementation was not completely finished and/or not fully tested. The test section SECTION("Constraints") in irc_test.h is commented out; see also 2b31dfc and 8f7f1cb. Therefore, making constraints work would require a bit of additional work, I think.

[AlexB67]

Thank you, It;s as i expected. Yes I saw the test case, uncommented and played around.

[RMeli]

Maybe @peterbygrave can give additional details here. Constraints seem to be implemented in Entos Envision, but I don't know if they are still using this library.