Hi there

I performed a CASTEP geometry optimization and it is found that the calculation was successful as per the status but when I open the output file, it looks like the calculation didn't converge. Any advice will be highly appreciated... 

+------------+-------------+-------------+-----------------+ <-- min TPSD
| Step | lambda | F.delta' | enthalpy | <-- min TPSD
+------------+-------------+-------------+-----------------+ <-- min TPSD
| previous | 0.000000 | 6.554500 | -42648.982347 | <-- min TPSD
| trial step | 0.000001 | 6.530131 | -42648.980635 | <-- min TPSD
+------------+-------------+-------------+-----------------+ <-- min TPSD
 
TPSD: finished iteration 72 with enthalpy= -4.26489806E+004 eV
 
+-----------+-----------------+-----------------+------------+-----+ <-- TPSD
| Parameter | value | tolerance | units | OK? | <-- TPSD
+-----------+-----------------+-----------------+------------+-----+ <-- TPSD
| dE/ion | 7.226968E-006 | 2.000000E-005 | eV | Yes | <-- TPSD
| |F|max | 2.331844E+000 | 5.000000E-002 | eV/A | No | <-- TPSD
| |dR|max | 4.186889E-008 | 2.000000E-003 | A | Yes | <-- TPSD
| Smax | 2.934695E+000 | 1.000000E-001 | GPa | No | <-- TPSD
+-----------+-----------------+-----------------+------------+-----+ <-- TPSD

================================================================================
Starting TPSD iteration 73 ...
================================================================================
TPSD: WARNING - vanishing step length
TPSD: WARNING - Geometry optimization failed to converge after 73 steps

================================================================================
TPSD: Final Configuration:
================================================================================