The Museum of HP Calculators


Miller Indices for Cubic Crystal for HP-33s

This program is by Ed Look and is used here by permission.

This program is supplied without representation or warranty of any kind. Ed Look and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.

Overview

This calculates the Miller indices for three planes from three peaks of an X-ray powder diffraction pattern, like the one for the HP-48G/G+/GX, except this one's for the 33s.

It requires input first of the crystal's lattice parameter, then three peaks from the powder pattern, in any order.

The output will be the lattice parameter as it was input, and then the three Miller index sets, one for each plane (peak).

Listing

Miller Indices (h k l) from Cubic X-Ray Diffraction Powder Patterns for the HP-33s

 
B0001	LBL B	this sets up the loop control
B0002	FIX 3
B0003	INPUT A	input of the lattice parameter
B0004	STO A
B0005	2.004
B0006	STO i
C0001	LBL C
C0002	INPUT Q	this input is actually 2θ (Q because the
C0003	2	HP-33s has no Greek letters
C0004	/
C0005	SIN
C0006	RCL A	this section (LBLs C, D, E, and F) is 
C0007		the calculation of the Miller indices
C0008	2	and loops to occur three times, which
C0009		accomodates three diffractogram peaks
C0010	1.54
C0011	/
C0012	x^2
C0013	STO(i)
C0014	FP
C0015	0.5
C0016	x>y?
C0017	GTO D
C0018	GTO F
D0001	LBL D
D0002	RCL(i)
D0003	IP
E0001	LBL E 	also in E is the formatting of the
E0002	ENTER	display of the indices in the 33s
E0003	√x
E0004	IP
E0005	100
E0006	
E0007	STO(i)
E0008	100
E0009	/
E0010	x^2
E0011	-
E0012	ENTER
E0013	√x
E0014	IP
E0015	10
E0016	
E0017	STO+(i)
E0018	10
E0019	/
E0020	x^2
E0021	-
E0022	√x
E0023	IP
E0024	STO+(i)
E0025	ISG i
E0026	GTO C
E0027	RCL A	display of the lattice parameter
E0028	PSE
E0029	RCL B	display of Miller indices of 1st plane
E0030	PSE
E0031	FIX 0
E0032	RCL C	display of Miller indices of 2nd plane
E0033	PSE
E0034	RCL D	display of Miller indices of 3rd plane
E0035	RTN	and this all fills the four stack levels
F0001	LBL F
F0002	RCL (i)
F0003	IP
F0004	1
F0005	+
F0006	GTO E
F0007	RTN

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