NATIONAL BUREAU OF STANDARDS REPORT

10 059

Progress Report

on SIMPLE EXTENSION OF MODEL MAKING TECHNIQUE

OF WOOD, GEITH, PAN LIANG AND DOCKRILL

<J05>

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards w as established by an act of Congress March 3. 1901 . Today,

in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal

focal point in the Federal Government for assuring maximum application of the physical and

engineering sciences to the advancement of technology in industry and commerce. To this end

the Bureau conducts research and provides central national services in four broad program

areas. These are: (1) basic measurements and standards. (2) materials measurements and

standards, (3) technological measurements and standards, and (4) transfer of technology.

The Bureau comprises the Institute for Basic Standards, the Institute for Materials Research, the

Institute for Applied Technology, the Center for Radiation Research, the Center for Computer

Sciences and Technology, and the Office for Information Programs.

THE INSTITUTE FOR BASIC STANDARDS provides the central basw within the United

States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and

uniform physical measurements throughout the Nation’s scientific community, industry, and commerce. The Institute consists of an Office of Measurement Services and the following technical

divisions:Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic and Molecular Physics-—Radio Physics J —Radio Engineering - —Time and Frequency -—Astrophysics -—Cryogenics.

THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to im- proved methods of measurement standards, and data on the properties of well-characterized

materials needed by industry, commerce, educational institutions, and Government: develops,

produces, and distributes standard reference materials: relates the physical and chemical properties of materials to their behavior and their interaction with their environments; and provides

advisory and research serv ices to other Government agencies. The Institute consists of an Office of Standard Reference Materials and the following divisions: Analytical Chemistry—Polymers—Metallurgy—Inorganic Materials—Physical Chemistry.

THE INSTITUTE FOR APPLIED TECHNOLOGY provides technical services to promote

the use of available technology and to facilitate technological innovation in industry and Government; cooperates with public and private organizations in the development of technological

standards, and test methodologies; and provides advisory and research services for Federal, state, and local government agencies. The Institute consists of the following technical divisions and

offices: Engineering Standards—Weights and Measures — Invention and Innovation — Vehicle Systems Research—Product Evaluation —Building Research—Instrument Shops—Measurement Engineering—Electronic Technology—Technical Analysis.

THE CENTER FOR RADIATION RESEARCH engages in research, measurement, and application of radiation to the solution of Bureau mission problems and the problems of other agencies and institutions. The Center consists of the following divisions: Reactor Radiation—Linac Radiation—Nuclear Radiation—Applied Radiation. THE CENTER FOR COMPUTER SCIENCES AND TECHNOLOGY conducts research and

provides technical services designed to aid Government agencies in the selection, acquisition, and effective use of automatic data processing equipment; and serves as the principal focus

for the development of Federal standards for automatic data processing equipment, techniques, and computer languages. The Center consists of the following offices and divisions: Information Processing Standards—Computer Information — Computer Services — Sys- tems Development—Information Processing Technology.

THE OFFICE FOR INFORMATION PROGRAMS promotes optimum dissemination and

accessibility of scientific information generated within NBS and other agencies of the Federal government; promotes the development of the National Standard Reference Data System and a system of information analysis centers dealing with the broader aspects of the National Measure- ment System, and provides appropriate services to ensure that the NBS staff has optimum accessibility to the scientific information of the world. The Office consists of the following

organizational units:

Office of Standard Reference Data—Clearinghouse for Federal Scientific and Technical Information —Office of Technical Information and Publications—Library—Office of Public Information—Office of International Relations.

1 Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted, mailing address Washington. D.C. 20234.

a Located at Boulder, Colorado 80302.

:l Located at 5285 Port Royal Road. Springfield. Virginia 22151.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT

31 1.05-11-311056 1 June 30, 1969

NBS REPORT

10 059

P rogress Report

on SIMPLE EXTENSION OF MODEL MAKING TECHNIQUE

OF WOOD, GEITH, PAN LIANG AND DOCKRILL

by

J. S. Bowen,* P. Kingsbury,* and B. Dickens*

* Research Associates of the American Dental Association,

Dental Research Section, National Bureau of Standards,

Washington, D. C. 20234 + Research Chemist, Dental Research Section, National

Bureau of Standards, Washington, D. C. 20234

This investigation is part of the dental research

program conducted by the National Bureau of Standards

and is supported by the National Institute for Dental

Research Collaborative Office.

IMPORTANT NOTICE NATIONAL BUREAU OF

for use within the Governmen

and review. For this reason, whole or in part, is not aut Bureau of Standards, Washin

the Report has been specitica

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 201 5.

;ress accounting documents intended

is subjected to additional evaluation

ire listing of this Report, either in the Office of the Director, National

•, by the Government agency for which

I copies for its own use. <NBS>

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

SIMPLE EXTENSION OF MODEL MAKING TECHNIQUE

OF WOOD, GEITH, PAN LIANG AND DOCKRILL

by

J. S. Bowen, P. B. Kingsbury and B. Dickens

In our structural Investigations of ionic compounds,

such as the calcium phosphates and hydrated carbonates,

we have found it essential to build, routinely, compact

(l A = 1 cm) and sturdy models (Figure l) which reveal

the packings In the crystal structures. We have adapted

a procedure suggested by Wood, Geith, Pan Liang and

Dockrill (1961) so that we can use readily available 3/8

inch diameter colored plastic beads and string each bead

on its own string without having to tie any knots.

Our method Is as follows: A list, conveniently

sorted, of all the atoms in a unit cell (translated back

into that cell where necessary) is made from the unique

set of atoms using a program written for the Univac 1108

computer. The list is used to prepare a template from

which two 1/2 Inch thick plexiglass plates are drilled

with a No. 60 (0.040 inch dia.) drill. The two plates

are separated by 1/2 inch diameter plexiglass rods, one

at each corner. As pointed out by Wood et al

.

, triclinic

cells are easily made by displacing the two plexiglass

sheets. One end of a 0.012 inch diameter nylon monofiliament fishing line is passed through a drilled hole

1
in one of the plates and secured by hammering in a

small nail. The appropriately colored beads are

threaded on with the fishing line passed through the

bead twice to generate enough friction to keep the

bead in place, but allow its height to be adjusted

readily. The string is then pulled tight and secured

in the other plate by another small nail, and the

heights of the beads are adjusted. When the model is

completed, a grid of the unit cells in the model, with

all atoms labelled, is attached to the bottom.

Using this method, we are able to assemble complex

models containing several unit cells fairly quickly

while avoiding the time-consuming and difficult operations of drilling plastic balls and tying knots in the

fishing line.

Reference

Wood, D. L.; Geith, C. R.j Pan Liang, C. Y. ; and

Dockrill, A. G. ActaCryst. 14:301 (1961).

USCOMM-NBS.DC

2
Figure 1

A Model of the Crystal Structure

of NagCCyHgO


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