Re: [NAMD] Problem with colvar "tilt"

From: Giacomo Fiorin (giacomo.fiorin_at_gmail.com)
Date: Fri May 12 2017 - 08:43:41 CDT

Hi Sebastian, the tilt variable does not support total force calculations:

http://colvars.github.io/colvars-refman-namd/colvars-
refman-namd.html#x1-530005.3.3

so you can either use one of the existing eABF implementations, or
alternatively, metadynamics, umbrella sampling, etc

Giacomo

On Fri, May 12, 2017 at 9:34 AM, The Cromicus Productions <
thecromicusproductions_at_gmail.com> wrote:

> Hi everyone,
>
> I'm trying to do ABF on two collective variables but the tilt one is
> giving me the following
> errors:
> colvars: No dependency satisfied among alternates:
> colvars: -----------------------------------------
> colvars: 1. extended Lagrangian
> colvars: Feature unavailable: "extended Lagrangian" in colvar
> TiltAngle
> colvars: 2. total force calculation
> colvars: Feature unavailable: "Jacobian derivative" in cvc tilt0001
> colvars: ...required by "Jacobian derivative" in colvar TiltAngle
> colvars: ...required by "total force calculation" in colvar TiltAngle
> colvars: -----------------------------------------
> colvars: for "total force" in colvar TiltAngle
> colvars: ...required by "obtain total force" in bias abf1
> colvars: Error: Failed dependency in bias abf1.
> FATAL ERROR: Error in the collective variables module: exiting.
>
> This is my definition of the collective variables. Any idea of what am I
> doing wrong?
> Thanks you very much!
>
> colvarsTrajFrequency 500
> colvarsRestartFrequency 20000
>
> colvar {
> name NormalMolMem
>
> width 0.05
>
> lowerBoundary 3
> lowerWallConstant 20.0
> upperBoundary 15
> upperWallConstant 20.0
>
> outputValue
> outputAppliedForce
>
> distanceZ {
> main {
> atomNumbers { 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164
> 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179
> 1180 1181 }
> }
> ref {
> atomNumbers { 6 8 14 16 22 24 30 32 38 40 46 48 54 56 62 64 70 72 78 80 86
> 88 94 96 102 104 110 112 118 120 126 128 134 136 142 144 150 152 158 160
> 166 168 174 176 182 184 190 192 198 200 206 208 214 216 222 224 230 232 238
> 240 246 248 254 256 262 264 270 272 278 280 286 288 294 296 302 304 310 312
> 318 320 326 328 334 336 342 344 350 352 358 360 366 368 374 376 382 384 390
> 392 398 400 406 408 414 416 422 424 430 432 438 440 446 448 454 456 462 464
> 470 472 478 480 486 488 494 496 502 504 510 512 518 520 526 528 534 536 542
> 544 550 552 558 560 566 568 574 576 582 584 590 592 598 600 606 608 614 616
> 622 624 630 632 638 640 646 648 654 656 662 664 670 672 678 680 686 688 694
> 696 702 704 710 712 718 720 726 728 734 736 742 744 750 752 758 760 766 768
> 774 776 782 784 790 792 798 800 806 808 814 816 822 824 830 832 838 840 846
> 848 854 856 862 864 870 872 878 880 886 888 894 896 902 904 910 912 918 920
> 926 928 934 936 942 944 950 952 958 960 966 968 974 976 982 984 990 992 998
> 1000 1006 1008 1014 1016 1022 1024 1030 1032 1038 1040 1046 1048 1054 1056
> 1062 1064 1070 1072 1078 1080 1086 1088 1094 1096 1102 1104 1110 1112 1118
> 1120 1126 1128 1134 1136 1142 1144 1150 1152 }
> }
> }
> }
>
> colvar {
> name TiltAngle
>
> width 0.05
>
> lowerBoundary -1
> lowerWallConstant 20.0
> upperBoundary 1
> upperWallConstant 20.0
>
> tilt {
> atoms {
> atomNumbers { 1162 1163 1165 1167 1169 1170 }
> }
> refPositions {
> (2.128,-7.221,-2.489) (3.177,-9.110,-2.489) (1.837,-10.595,-2.489)
> (3.561,-12.419,-2.489) (4.828,-7.499,-2.489) (5.536,-9.607,-2.489)
> }
> }
> }
>
>
>
>
> abf {
> colvars NormalMolMem TiltAngle
> fullSamples 500
> historyFreq 20000
> }
>
>
> -------------------------------------
> Sebastian
>

-- 
Giacomo Fiorin
Associate Professor of Research, Temple University, Philadelphia, PA
Contractor, National Institutes of Health, Bethesda, MD
http://goo.gl/Q3TBQU
https://github.com/giacomofiorin

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