Hi Jeff, > There used to be a WHAT IF web interface in which a user could submit a > PDB ID number and get back an "hadded.pdb" file with hydrogen atoms > added. This site no longer exists, and the WHAT IF software is now only > available to those who purchase it for 500 Euros (at > http://swift.cmbi.kun.nl/whatif/). The new URL for this server is http://swift.cmbi.kun.nl/WIWWWI/ (btw, the price of WHAT IF is still 250 EUR for the Linux version ;-). If you want to work locally, you can also download YASARA View ( http://www.yasara.org/viewdl ), and click on Edit > Add > Hydrogens to all. But only the WHAT IF server will do elaborate things like flipping Asn, Gln, His side-chains to optimize the hydrogen bonding network. Greetings, Elmar -- Elmar Krieger, PhD YASARA Biosciences & CMBI Outstation Austria Neue-Welt-Hoehe 13/b A-8042 Graz Austria/Europe Ww c(@@)c ================()==OUu============ =WHAT IF YASARA knows the answer?!= =----- http://www.yasara.org -----= =- http://www.cmbi.ru.nl/whatif -= ============OOo==================== () () _/ /_