In MD movie I loaded complex.prmtop and complex.inpcrd files In Tools/Amber/Add ions I selected Ion types Na+ to neutralise complex.inpcrd using AMBER ff14SB for standard residues and AM1-BCC for other residues (I’m attaching a snapshot showing the Na+ ions in red). I then proceeded to solvate the complex using TIP3PBOX and Box size: 9 NOTE: I unticked the Removed existing ions/solvent box I obtained the following Warning “Could not determine charges for pre-existing solvent/ions from added solvent/ions for: NA NA I generated complex_solv.prmtop and complex_solv.inpcrd files When I checked the complex_solv.prmtop file in cpptraj, I did not see any of the Na+ions (see below).
resinfo #Res Name First Last Natom #Orig #Mol 1 ASP 1 14 14 1 1 2 THR 15 28 14 2 1 ——————— 250 LEU 3988 4006 19 250 3 251 VAL 4007 4023 17 251 3 252 KBR 4024 4062 39 252 4 253 WAT 4063 4065 3 253 5 ———— 10272 WAT 34084 34086 3 10272 10024 10273 WAT 34087 34089 3 10273 10025
Is this what should be expected? Should I consider the solvated complex charge neutralised? Antechamber generated exactly the corresponding complex_solv.prmtop file with Na+ ions Thank you in advance for any suggestions.
