Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Gaithersburg

Security Test Assertions for VVSG 1.1, Section 7, September, 2016

Section 7 of the VVSG 1.1 contains requirements for security. NIST has completed a set of draft test assertions for the security...

QA/CM Test Assertions for VVSG 1.1, September, 2016

VVSG 1.1 Volume 1, Section 8, contains requirements for QA/CM, as does Volume 2, Section 2.1. NIST has completed a set of test assertions...

Methane Symmetry Operations - Symmetry Properties of Rotational Wave functions and Direction Cosines

7. Symmetry Properties of Rotational Wave functions and Direction Cosines It is in the determination of symmetry properties of functions of...

Methane Symmetry Operations - Symmetry Properties of Vibrational Functions

6. Symmetry Properties of Vibrational Functions Vibrational symmetry coordinates for CH 4 can be written as $$\begin{eqnarray*...

Methane Symmetry Operations - Subgroup and Full Group

5. The Subgroup D 2 dvs. the Full Group T d The spherical-top point group T d is more complicated to treat than any of the symmetric-top or...

Methane Symmetry Operations - Explicit Eulerian-Angle transformations

4.4 Explicit Eulerian-Angle transformations For 16 of the 24 operations in the point group T d, the explicit transformations of the...

Methane Symmetry Operations - Improper rotations

4.3 Improper rotations Consider now a sense-reversing point-group operation, represented by the rotation-reflection symbol S n. (Formally...

Methane Symmetry Operations - Proper rotations

4.2 Proper rotations Consider first a proper-rotation point-group operation C n , since proper rotations represent a slightly easier case...

Methane Symmetry Operations - Figure 4

Figure 4. (a) An arbitrary instantaneous configuration of the methane molecule; (b) rotation of vibrational displacement vectors through an...

Methane Symmetry Operations - Figure 3

Figure 3. (a) An arbitrary instantaneous configuration of the methane molecule; (b) rotation of vibrational displacement vectors through an...

Methane Symmetry Operations - Figure 2

Figure 2. Illustration of the generation of nuclear coordinates R i in the laboratory-fixed axis system XYZ by: (a) placing the nuclei at...

Methane Symmetry Operations - Relation of Point-Group Operations to Permutation-Inversion Group Operations

4. Relation of Point-Group Operations to Permutation-Inversion Group Operations 4.1 Algebraic equation relating laboratory-fixed...

Methane Symmetry Operations - Permutation-Inversion

3. Permutation-Inversion Group Ideas Longuet-Higgins [ 1] has pointed out that an alternative and more powerful way of treating molecular...

Methane Symmetry Operations - Table 4

Table 4. Transformation matrices D E( P) for ( eq. 6) The transposes of these matrices form a representation of the point group T d of...

Methane Symmetry Operations - Table 3

Table 3. Transformation matrices D F 1( P) for ( eq. 5) The transposes of these matrices form a representation of the point group T d of...

Methane Symmetry Operations - Representation Matrices

2.3 Representation Matrices The transposes of the matrices D(P) given in Table 2 form a representation [ 22] of the point group T d...

Methane Symmetry Operations - Table 2

Table 2. Transformation matrices D( P) for ( eq. 1) The transposes of these matrices form a representation of the point group T d of species...

Methane Symmetry Operations - Algebraic operations

2.2 Algebraic operations The geometrical operations can be transformed into algebraic operations by asking: what are the new coordinates...

Methane Symmetry Operations - Geometric operations

2. Familiar Point Group Ideas 2.1 Geometric operations Figure 1 illustrates the four hydrogens of CH 4 numbered [ 17] and placed at the...

Methane Symmetry Operations - Introduction

1. Introduction The goal of this article, a more detailed title for which is "a catalogue of explicit symmetry operations for the...

Methane Symmetry Operations - Version History

Example of how to reference this online document: (Replace year, month day with database access date.) J.T. Hougen (2001). "Methane...

NIST Grants Take Regional Approach to Solve National Cybersecurity Challenge

September 20, 2016

GAITHERSBURG, Md.—The U.S. Commerce Department’s National Institute of Standards and Technology (NIST) has awarded grants totaling nearly $1 million for five

Comparisons (Archive): Analysis of a new candidate Certified Reference Material (CRM) prepared by the International Atomic Energy Agency (IAEA)

An international measurement intercomparison exercise for radioactivity determination in Baltic Sea sediment started for a new IAEA CRM development.

Was this page helpful?