[Pw_forum] how to set nr1b, nr2b, nr3b for cp.x when using ultrasoft pseudopotential

[Uli Aschauer]

Dear Vega,

it seems that you're mixing pw.x input in your cp.x input. There is no 
such such thing as mixing_beta and nosym in cp.x (check the manual). 
Also your system is way too large to converge the wavefunction in 80 
steps, which is needed to get reasonable forces on the ions. There are 
other I suggest you start from a cp.x example to understand how to 
perform a sequence of cp.x runs.

Also please not the changing the dt in AUTOPILOT does not work as the 
dt2bye variable is calculated outside the main loop in cpr.f90 and is 
thus never updated upon AUTOPILOT events. You will have to move the 
calculation of dt2bye inside to make it work.

Best regards,
-uli

_________________________________________________________
Uli Aschauer
Princeton University
Chemistry Department
Frick Laboratory, Room 213
Princeton, NJ 08544
Tel: +1-609-258-0116
Email: aschauer at princeton.edu
_________________________________________________________

>
> Dear all,
>
> Sorry for last arbitrary question. I found there was a code called cppp.x.
>
> But now I encounter another serious problem with the information from 
> pp.x of "ortho went bananas", when I try to add nose thermostat to the 
> system at 150th step.
>
> the process as follows,
> First, I get the optimized geometry from the pw.x. Then I use that 
> geometry as the initial input to pp.x.
> During the first 19 of cp calculation, I did a few electronic steps 
> with ions fixed and dt=1
> From 20th step to 79th step, I enlarge the dt to 3;
> From 80th step to 149th step, I allow the ions to move and set dt to 
> 5, with no thermostat.
> When I tried to add nose thermostat, the "econt" of the system became 
> to NaN and the vnhp became to Inf.
> And then the program crashed with the information that "ortho went 
> bananas"
>  
> here is a part of my input files,
>  &CONTROL                                                                                 
>
>                        title = 'CPMD' 
> ,                                       
>                  calculation = 'cp' 
> ,                                                 
>                 restart_mode = 'from_scratch' 
> ,                                          
>                       outdir = '/tmp/' ,  
>                       wfcdir = '/tmp/' 
> ,                                                 
>                   pseudo_dir = '/home/vega/espresso-4.0/pseudo/' ,    
>                       prefix = 'cp_dissociation1' ,
>                       nstep = 99999 ,
>                           dt = 
> 1,                                                   
>  /                                                                                        
>
>  &SYSTEM                                                                                  
>
>                        ibrav = 
> 8,                                                        
>                    celldm(1) =24.8624,
>                    celldm(2) = 0.8520,
>                    celldm(3) = 1.6964,
>                          nat = 
> 147,                                                      
>                         ntyp = 3,
>                         nr1b = 20,
>                         nr2b = 20,
>                         nr3b = 
> 20,                                                        
>                        nosym = .true. 
> ,                                                  
>                    ecutwfc   =   30,
>                    ecutrho   =  300,
>  /                                                                              
>
>          
>  &ELECTRONS                         
>                  mixing_mode ='local-TF',
>                  mixing_beta = 0.4,  
>                  electron_dynamics = 'damp',                        
>  /                                                                             
>
>  &IONS                                                                                    
>
>                 ion_dynamics = 'none',
>              ion_temperature = 
> 'not_controlled',                                               
>  /
> AUTOPILOT
>     on_step =  20  : dt=3
>     on_step =  20  : electron_dynamics = 'damp'
>     on_step =  80  : dt=5
>     on_step =  80  : ion_dynamics    = 'damp'
>     on_step = 150  : ion_temperature = 'nose'
> ENDRULES                                                                                       
>
> ATOMIC_SPECIES                                                                            
>
> ......
> ......
> ......
>
> could you please do me a favor to tell me what is going wrong.
>
> best wishes,
>
> vega