[DFTB-Plus-User] The value of pressure after geometry optimization

[Moyassar Meshhal]

Dear dftb+ users,

Below is the last part of the output file of a geometry optimization job for a periodic system (namely, graphene oxide).
Although the geometry is converged, I noticed that the value of the pressure is quite high (0.565001E+10)!
Is this normal? or what I missed?
BTW, I didn't set any value for the external pressure in the input file, so the default value is used (which I guess to be 0.0, isn't it?).
I would appreciate an explanation, as well as any recommendation that might improve my calculations.

Best Regards,
Moyassar

-----------------
 iSCC Total electronic   Diff electronic      SCC error
    1   -0.18929725E+03    0.00000000E+00    0.27230171E-03
    2   -0.18929725E+03   -0.60135307E-07    0.11783150E-03
    3   -0.18929725E+03   -0.63194534E-08    0.56211281E-04
    4   -0.18929725E+03   -0.25149518E-08    0.29964703E-04
    5   -0.18929725E+03   -0.22265567E-09    0.65231892E-05

Total Energy:                     -186.0771157290 H        -5063.4159 eV
Extrapolated to 0:                -186.0771157324 H        -5063.4159 eV
Total Mermin free energy:         -186.0771157358 H        -5063.4159 eV
Force related energy:             -186.0771157358 H        -5063.4159 eV
Volume:                              0.849771E+04 au^3   0.125923E+04 A^3
Pressure:                            0.192040E-03 au     0.565001E+10 Pa
Maximal force component:             0.731554E-04
>> Charges saved for restart in charges.bin

Geometry converged

--------------------------------------------------------------------------------
DFTB+ running times                          cpu [s]             wall clock [s]
--------------------------------------------------------------------------------
Pre-SCC initialisation                 +   249.76  ( 11.9%)    140.69  (  9.7%)
SCC                                    +  1297.50  ( 61.9%)   1134.72  ( 78.3%)
Post-SCC processing                    +   549.67  ( 26.2%)    174.55  ( 12.0%)
--------------------------------------------------------------------------------
Missing                                +     0.15  (  0.0%)      0.01  (  0.0%)
Total                                  =  2097.08  (100.0%)   1449.98  (100.0%)
--------------------------------------------------------------------------------


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