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Subroutine MAP_CRYSTAL_ED2

  1. Provenance of code.
  2. Purpose of code.
  3. Specification.
  4. Description of subroutine's operation.
  5. References.
  6. Parameter descriptions.
  7. Error indicators.
  8. Accuracy estimate.
  9. Any additional information.
  10. Example of code
  11. Auxiliary subroutines required.
  12. Keywords.
  13. Download source code.
  14. Links.

Provenance of Source Code

H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.

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Purpose

To perform electron diffraction analysis in cases where the camera constant is unknown.

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Specification

Language:FORTRAN
Product form:Source code

SUBROUTINE MAP_CRYSTAL_ED2(F, ACCU, AAA, PI, RR, J21, JTYPE,
&AH, AK, AL, AAD, AHH, AKK, ALL, ABD, AU1, AV1, AW1, AAX, JA)

REAL F(9), ACCU, AAA, PI, RR, AH(400), AK(400), AL(400), AAD(400),
&AHH(400), AKK(400), ALL(400), ABD(400), AU1(400), AV1(400), AW1(400),
&AAX(400)

INTEGER J50, J21, JTYPE, JA

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Description

MAP_CRYSTAL_ED2 perform electron diffraction analysis for cases where the camera constant is unknown. It requires as input the ratio of the lengths of two reciprocal lattice vectors, as measured from the diffraction pattern. Calculations are made for a set of Miller indices which vary within a specified range.

If the camera constant is known, then the subroutine MAP_CRYSTAL_ED1 may be used instead.

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References

  1. H.K.D.H. Bhadeshia, Worked Examples in the Geometry of Crystals, Institute of Materials, London, 1987.
  2. H.K.D.H. Bhadeshia, Chapter on Crystallography in Microstructural Characterisation of High Temperature Materials, ed. E. Metcalfe, Institute of Metals, London, 1988.

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Parameters

Input parameters

F - real array of dimension 9
F converts components from reciprocal to real space.

ACCU - real
ACCU is the accuracy of measurement. A typical value is 0.03. If the input value of ACCU is greater than 0.08 it is reset to 0.08.

AAA - real
AAA is the acute angle between the vectors (in degrees).

RR - real
RR is the ratio of the d-spacings.

J21 - integer
J21 is the maximum range of the Miller index. A typical value is 3.

PI - real
PI is pi.

JTYPE - integer
JTYPE denotes the lattice type:-
JTYPE = 1 is for primitive
JTYPE = 2 is for body centered (cubic, tetragonal, orthorhombic)
JTYPE = 3 is for face centered (cubic, orthorhombic)
JTYPE = 4 is for A-centered (orthorhombic)
JTYPE = 5 is for B-centered (orthorhombic)
JTYPE = 6 is for C-centered (orthorhombic, monoclinic)

Output parameters

JA - integer
JA is the total number of vector pairs tested.

AH, AK, AL - real arrays of dimension JA
AH, AK, AL contain the varying Miller indices used for the first vector.

AAD - real array of dimension JA
AAD(I) contains the d-spacing for AH(I), AK(I), AL(I).

AHH, AKK, ALL - real arrays of dimension JA
AHH, AKK, ALL contains the varying Miller indices used for the second vector.

ABD - real array of dimension JA
ABD(I) contains the d-spacing for AHH(I), AKK(I), ALL(I).

AU1, AV1, AW1 - real arrays of dimension JA
AU1, AV1, AW1 contain the normalised components of the zone axis.

AAX - real array of dimension JA
AAX contains the angles between the lattice vectors.

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Error Indicators

None.

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Accuracy

No information supplied.

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Further Comments

None.

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Example

1. Program text

       REAL F(9), ACCU, AAA, PI, RR, AH(400), AK(400), AL(400)
       REAL AAD(400), AHH(400), AKK(400), ALL(400), ABD(400)
       REAL AU1(400), AV1(400), AW1(400), AAX(400)
       INTEGER J21, JTYPE, JA, I
       INCLUDE 'map_constants_pi.f'
       READ (5,*) (F(I), I=1,9)
       READ (5,*) ACCU, AAA, RR
       READ (5,*) J21, JTYPE
       CALL MAP_CRYSTAL_ED2(F, ACCU, AAA, PI, RR, J21,
&      JTYPE, AH, AK, AL, AAD, AHH, AKK, ALL, ABD, AU1, AV1, AW1, AAX, JA)
       WRITE (6,10) JA
10     FORMAT ('Total number of vector pairs tested is ', I4)
       WRITE (6,20) 
       DO 21 I=1, JA
        WRITE (6,30) AH(I), AK(I), AL(I), AAD(I)
21     CONTINUE
       WRITE (6,40)
       DO 41 I=1, JA
        WRITE (6,30) AHH(I), AKK(I), ALL(I), ABD(I)
41     CONTINUE
       WRITE (6,50) 
       DO 51 I=1, JA
        WRITE (6,30) AU1(I), AV1(I), AW1(I), AAX(I)
51     CONTINUE
20     FORMAT(,'Miller indices of 1st vector and d-spacing')
30     FORMAT(3F8.4,'     ',F8.4)
40     FORMAT(,'Miller indices of 2nd vector and d-spacing')
50     FORMAT(,'Cpts of zone axis and angles between lattice vectors')
       STOP
       END

2. Program data

1.0   0.0   0.0   0.0   1.0   0.0   0.0   0.0   0.25
0.03
3   2

3. Program results

None supplied.

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Auxiliary Routines

MAP_CRYSTAL_TEST2

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Keywords

camera constant, d-spacing, Miller index

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Download

Download source code

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