# [gmx-users] Reg: REMD result

Rohit Farmer rohit.bioinfo at gmail.com
Fri Jan 20 17:53:15 CET 2012

```Hi there,

I just run a REMD using just two replicas and extracted the results
using the following

grep Repl md0.log
Initializing Replica Exchange
Repl  There are 2 replicas:
Repl  Using Constant Pressure REMD.
Replica-exchange {M}onte {C}arlo method for the isobaric-isothermal ensemble
Repl      0     1
Repl  T 300.0 310.7
Repl  p  1.00  1.00
Repl
Repl  exchange interval: 1000
Repl  random seed: 13622
Repl  below: x=exchange, pr=probability
Replica exchange at step 1000 time 2
Repl 0 <-> 1  dE =  2.813e+01  dpV =  0.000e+00  d =  2.813e+01
Repl ex  0    1
Repl pr   .00
Replica exchange at step 2000 time 4
Repl ex  0    1
Repl pr
Replica exchange at step 3000 time 6
Repl 0 <-> 1  dE =  3.251e+01  dpV =  0.000e+00  d =  3.251e+01
Repl ex  0    1
Repl pr   .00
Replica exchange at step 4000 time 8
Repl ex  0    1
Repl pr
Replica exchange at step 5000 time 10
Repl 0 <-> 1  dE =  2.442e+01  dpV =  0.000e+00  d =  2.442e+01
Repl ex  0    1
Repl pr   .00
Replica exchange at step 6000 time 12
Repl ex  0    1
Repl pr
Replica exchange at step 7000 time 14
Repl 0 <-> 1  dE =  1.712e+01  dpV =  0.000e+00  d =  1.712e+01
Repl ex  0    1
Repl pr   .00
..................
..................
.................
Replica exchange statistics
Repl  49 attempts, 25 odd, 24 even
Repl  average probabilities:
Repl     0    1
Repl      .00
Repl  number of exchanges:
Repl     0    1
Repl        0
Repl  average number of exchanges:
Repl     0    1
Repl      .00

I couldn't understand the result according to this output it seems no
exchange has taken place. What should be the output if an exchange has
occurred.

Thanks

Rohit

--
Rohit Farmer
PhD Biosciences (2011-2014)
Center for Systems Biology
University of Birmingham
Birmingham B152TT
United Kingdom
Email : rohit.farmer at gmail.com

```