[Wien] Problem Energy Sep LAPW2 ACTUALLY MKL PROBLEM

[David Tompsett]

Dear All,

I recently wrote to the list facing problems with strange eigenvalues 
leading to errors in lapw2. I have solved the issue and thought I would 
write to the list as the actual cause is due to errors in MKL 10.1 and 
early 10.2 documented at:

http://software.intel.com/en-us/articles/dgemm-and-sgemm-accuracy/

I am not sure if these problems have been mentioned on the list before, 
but may affect anyone who has built Wien2k with any of the affected 
versions of Intel MKL. The errors only occur when the system size is 
such that the matrix sizes in lapw1 satisfy the criteria listed at the 
link above. Thus it may appear that one's code is working well and then 
odd errors will occur for particular cases.

After rebuilding my Wien2k with either old MKL 9.1 or the latest 
10.2.2.025 the problems disappeared.

Best wishes,
David Tompsett.

-- 
David A. Tompsett
Quantum Matter Group
Cavendish Laboratory
J. J. Thomson Avenue
Cambridge CB3 0HE
U.K.
Tel: +44 7907 566351 (mobile)
Fax: +44 1223 768140
http://www-qm.phy.cam.ac.uk/


Peter Blaha wrote:
> You said, this happens already in the first iteration ?
>
> What are your RMT values of all atoms ?   RKmax ?
>
> Are you sure, your structure is correct ?
>
> The message 15 eigenvalues below -9. indicates that much more is 
> incorrect than just the energy parameters of atom 24.
>
> I don't think you should put the E-parameters to -8 Ry. Probably you 
> do not expect eigenvalues in this range.
>
> Hard to guess what you could have made wrong.
>
> David Tompsett schrieb:
>> Dear Peter and All,
>>
>> Thank you for the help. From the case.output2 files it seems that the 
>> problem is with very low lying p-states:
>>  QTL-B VALUE .EQ. 1876.88467   in Band of energy   -8.53431   ATOM=   
>> 24   L=  1
>>    Check for ghostbands or EIGENVALUES BELOW XX messages
>>    Adjust your Energy-parameters or use -in1new switch, check RMTs  !!!
>>
>> My linearization energies for this atom are:
>> 0.60    5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
>> APW/LAPW)
>> 0    0.60      0.000 CONT 1
>> 0   -4.00      0.005 STOP 1
>> 1   -2.21      0.010 CONT 1
>> 1    0.60      0.000 CONT 1
>> 2    0.60      0.010 CONT 1
>>
>> My first thought is to alter -2.21 to -8.00 for the p-state LO, but I 
>> am concerned that since -8.53431 is so low that somehow my 
>> calculation window is including multiple p-states ie. more than two 
>> sets of p-states.
>> Also, the case.output1 file says that there are:
>>           15 EIGENVALUES BELOW THE ENERGY   -9.00000
>>       ********************************************************
>>
>> Please advise me as to how to proceed.
>>
>> Thank you,
>> David.
>>
>> Peter Blaha wrote:
>>> You are doing k-parallel calc !
>>>
>>> What says     lse   ?
>>> Check the individual case.output2_xx files !
>>>
>>> David Tompsett schrieb:
>>>> Dear Peter and All,
>>>>
>>>> the end of my case.output2 looks as follows and confirms that there 
>>>> is some error in finding the separation of semi-core and valence 
>>>> states, though from the userguide it seems that this should not be 
>>>> a major issue without using -in1new.
>>>>
>>>> eseper below EF  0.500000000000000    eseper minimum gap  
>>>> 5.000000000000000E-002
>>>> Energy to separate semicore and valence states:  -999.000000000000  
>>>> :NOE  : NUMBER OF ELECTRONS          =1313.000
>>>>
>>>> :FER  : F E R M I - ENERGY(TETRAH.M.)=   0.94199
>>>> NbFe2Super222NM.weigh                                                          
>>>>
>>>>                                                                               
>>>>
>>>>                                 8
>>>> writing
>>>> NbFe2Super222NM.weigh_1                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_2                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_3                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_4                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_5                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_6                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_7                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     writing
>>>> NbFe2Super222NM.weigh_8                                                        
>>>>
>>>>                                                                               
>>>>
>>>>                     NK           8
>>>>
>>>> Otherwise the file seems OK and I copy the rest of it below 
>>>> (excluding the KVEC list). The error is occurring on the very first 
>>>> SCF cycle each time.
>>>>
>>>> Many thanks for any more help,
>>>> David.
>>>>
>>>
>>
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