# Prodrg server **URL:** \ **Category:** User discussions\ **Created:** [December 4, 2023, 8:43am UTC](https://gromacs.bioexcel.eu/t/prodrg-server/7782 "2023-12-04T08:43:08Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![sayan23us](https://avatars.discourse-cdn.com/v4/letter/s/65b543/32.png) [@sayan23us](https://gromacs.bioexcel.eu/u/sayan23us)\ **Post date:** [December 4, 2023, 8:43am UTC](https://gromacs.bioexcel.eu/t/prodrg-server/7782/1 "2023-12-04T08:43:08Z")
GROMACS version:any GROMACS modification: Yes are there any alternative for prodrg server? ---
**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\ **Post date:** [December 7, 2023, 2:39pm UTC](https://gromacs.bioexcel.eu/t/prodrg-server/7782/2 "2023-12-07T14:39:47Z")
Use ATB. One should never use PRODRG; in fact, the original author took it offline for a time (and may still have it down) because it was only ever intended for crystal refinement, not MD simulations. There is a major bug in PRODRG related to charge assignment that renders it inappropriate to use for any serious simulation work. ---
**Author:** ![sayan23us](https://avatars.discourse-cdn.com/v4/letter/s/65b543/32.png) [@sayan23us](https://gromacs.bioexcel.eu/u/sayan23us)\ **Post date:** [December 12, 2023, 10:28am UTC](https://gromacs.bioexcel.eu/t/prodrg-server/7782/3 "2023-12-12T10:28:17Z")
Thanks for your reply. Can you provide any tutorial for using ATB.Can you inform me how to calculate net charge of a particular molecule ?are there any software available for that? ---
**Author:** ![Teslim](https://avatars.discourse-cdn.com/v4/letter/t/f1d935/32.png) [@Teslim](https://gromacs.bioexcel.eu/u/Teslim)\ **Post date:** [December 12, 2023, 2:36pm UTC](https://gromacs.bioexcel.eu/t/prodrg-server/7782/4 "2023-12-12T14:36:59Z")
you should know that based on the molecules that you are working with