Small tweaks to MTS-RPC tutorial (#100)

* Small tweaks to MTS-RPC tutorial

Author: ceriottm

examples/pi-mts-rpc/data/h2o_md.xml

@@ -4,7 +4,7 @@
     <trajectory filename='pos' stride='100' format='xyz' cell_units='angstrom'> positions{angstrom} </trajectory>
     <checkpoint filename='checkpoint' stride='1000' overwrite='True'/>
   </output>
-  <total_steps> 10000 </total_steps>
+  <total_steps> 20000 </total_steps>
   <ffsocket mode='unix' name='qtip4pf' pbc='false'>
       <address>qtip4pf-md</address>
   </ffsocket>  
@@ -23,7 +23,7 @@
       <dynamics mode='nvt'>
           <timestep units='femtosecond'> 0.5 </timestep>
           <thermostat mode="svr">
-             <tau units="femtosecond"> 400 </tau>
+             <tau units="femtosecond"> 500 </tau>
           </thermostat>
       </dynamics>
     </motion>

examples/pi-mts-rpc/data/h2o_mts.xml

@@ -4,7 +4,7 @@
     <trajectory filename='pos' stride='100' format='xyz' cell_units='angstrom'> positions{angstrom} </trajectory>
     <checkpoint filename='checkpoint' stride='1000' overwrite='True'/>
   </output>
-  <total_steps> 2500 </total_steps>
+  <total_steps> 5000 </total_steps>
   <ffsocket mode='unix' name='qtip4pf' pbc='false'>
       <address>qtip4pf-mts-full</address>
   </ffsocket>
@@ -32,7 +32,7 @@
           <timestep units='femtosecond'> 2.0 </timestep>
           <nmts>[1,4]</nmts>
           <thermostat mode="svr">
-             <tau units="femtosecond"> 400 </tau>
+             <tau units="femtosecond"> 500 </tau>
           </thermostat>
       </dynamics>
     </motion>

examples/pi-mts-rpc/mts-rpc.py

@@ -663,6 +663,8 @@ def autocorrelate(x, xbar=None, normalize=True):
 ax[1].plot(rpcmts_output["time"], rpcmts_output["kinetic_cv"], "m.", label="RPC-MTS")
 ax[1].set_xlabel("t / ps")
 ax[1].set_ylabel("K / eV")
+ax[0].set_xlim(0.0, 5.0)
+ax[1].set_xlim(0.0, 5.0)
 ax[0].legend()
 
 # %%