ARL-TN-0785 ● SEP 2016

US Army Research Laboratory

Theoretical Prediction of the Heats of Formation, 

Densities, and Relative Sensitivities for 1,7-dinitro3,4,5,8-tetra N-oxide-bis([1,2,3]triazolo)[4,5-

b:5',4'-e]pyrazine, 1,7-dinitro-3,5,8-tri N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine, 1,7-

dinitro-3,5-bis N-oxide-bis([1,2,3]triazolo)[4,5-

b:5',4'-e]pyrazine, 1,7-dinitro-1,7-

dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-e]pyrazine

by Edward FC Byrd

Approved for public release; distribution is unlimited.
NOTICES

Disclaimers

The findings in this report are not to be construed as an official Department of the 

Army position unless so designated by other authorized documents.

Citation of manufacturer’s or trade names does not constitute an official 

endorsement or approval of the use thereof.

Destroy this report when it is no longer needed. Do not return it to the originator.
ARL-TN-0785 ● SEP 2016

US Army Research Laboratory

Theoretical Prediction of the Heats of Formation, 

Densities, and Relative Sensitivities for 1,7-dinitro3,4,5,8-tetra N-oxide-bis([1,2,3]triazolo)[4,5-

b:5',4'-e]pyrazine, 1,7-dinitro-3,5,8-tri N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine, 1,7-

dinitro-3,5-bis N-oxide-bis([1,2,3]triazolo)[4,5-

b:5',4'-e]pyrazine, 1,7-dinitro-1,7-

dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-e]pyrazine

by Edward FC Byrd

Weapons and Materials Research Directorate, ARL

Approved for public release; distribution is unlimited.
ii

REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the 

data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the 

burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. 

Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid 

OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

September 2016

2. REPORT TYPE

Technical Note

3. DATES COVERED (From - To)

1 November 2015–31 December 2015

4. TITLE AND SUBTITLE

Theoretical Prediction of the Heats of Formation, Densities, and Relative 

Sensitivities for 1,7-dinitro-3,4,5,8-tetra N-oxide-bis([1,2,3]triazolo)[4,5-b:5',4'-

e]pyrazine, 1,7-dinitro-3,5,8-tri N-oxide-bis([1,2,3]triazolo)[4,5-b:5',4'-

e]pyrazine, 1,7-dinitro-3,5-bis N-oxide-bis([1,2,3]triazolo)[4,5-b:5',4'-

e]pyrazine, 1,7-dinitro-1,7-dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-e]pyrazine

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Edward FC Byrd

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

US Army Research Laboratory

ATTN: RDRL-WML-B

Aberdeen Proving Ground, MD 21005-5069

8. PERFORMING ORGANIZATION REPORT NUMBER

ARL-TN-0785

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)

11. SPONSOR/MONITOR'S REPORT NUMBER(S)

12. DISTRIBUTION/AVAILABILITY STATEMENT

Approved for public release; distribution is unlimited.

13. SUPPLEMENTARY NOTES

14. ABSTRACT

Using the US Army Research Laboratory–developed series of scripts, written to dramatically simplify the computation of 

crystalline density and heat of formation, the performance properties for the 1,7-dinitro-3,4,5,8-tetra N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (1), 1,7-dinitro-3,5,8-tri N-oxide-bis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (2), 1,7-

dinitro-3,5-bis N-oxide-bis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (3), 1,7-dinitro-1,7-dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-

e]pyrazine (4) notional energetic materials were evaluated. Additionally, a qualitative estimation of the impact sensitivities has

been calculated. This report outlines the procedures used to generate this information, as well as Cheetah calculations, using 

the predicted crystalline density and heat of formation.

15. SUBJECT TERMS

computational toolkit, quantum molecular dynamics, computational toolbox, script, crystalline density, heat of formation, 

impact sensitivity, energetic materials

16. SECURITY CLASSIFICATION OF:

17. LIMITATION

OF ABSTRACT

UU

18. NUMBER

OF PAGES

16

19a. NAME OF RESPONSIBLE PERSON

Edward FC Byrd

a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified

19b. TELEPHONE NUMBER (Include area code)

410-306-0729

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18
Approved for public release; distribution is unlimited.

iii

Contents

List of Figures iv

List of Tables iv

Acknowledgments v

1. Introduction 1

2. Results and Discussion 1

3. Conclusions 5

4. References 6

List of Symbols, Abbreviations, and Acronyms 7

Distribution List 8
Approved for public release; distribution is unlimited.

iv

List of Figures

Fig. 1 Optimized structure of a) 1, b) 2, c) 3, d) 4 ...........................................2

Fig. 2 Electrostatic potential map of 1, without a) and with b) molecule 

overlay....................................................................................................3

Fig. 3 Electrostatic potential map of 2, without a) and with b) molecule 

overlay....................................................................................................3

Fig. 4 Electrostatic potential map of 3, without a) and with b) molecule 

overlay....................................................................................................4

Fig. 5 Electrostatic potential map of 4, without a) and with b) molecule 

overlay....................................................................................................4

List of Tables

Table 1 Computed heats of formation and crystalline densities for the 

molecules ...............................................................................................2

Table 2 Cheetah predicted properties for 1, 2, 3, and 4 ......................................4
Approved for public release; distribution is unlimited.

v

Acknowledgments

Dr Betsy Rice and Jennifer J Hare are acknowledged for their efforts in the original 

coding of the neutral heat of formation and EDAT tools, respectively. Dr Anthony 

Yau is acknowledged for his work in revising the EDAT code. Dr James Ianni

(Applications Engineer with Lockheed-Martin, contractor to the US Army 

Research Laboratory [ARL] Department of Defense [DOD] Supercomputing 

Resource Center [DSRC]) is acknowledged for his “gsubmit” script, initially 

written for the ARL DSRC. Dr Betsy Rice is acknowledged for running the Cheetah 

calculations. All computations were performed at the ARL DSRC, Aberdeen 

Proving Ground, Maryland. Calculations were performed at the behest of Dr Joseph 

Mannion (Naval Surface Warfare Center – Indian Head).
Approved for public release; distribution is unlimited.

vi

INTENTIONALLY LEFT BLANK.
Approved for public release; distribution is unlimited.

1

1. Introduction

US Army Research Laboratory (ARL) researchers have achieved robust theoretical 

models capable of predicting performance properties, such as heats of formation,1,2

densities,3,4 and impact sensitivity5 of energetic materials and have begun growing 

advanced synthesis capabilities to realize notional materials. This dual capability 

allows synthetic and formulation chemists to safely and quickly screen candidate 

materials to focus efforts only on the most promising compounds. For an in-depth 

explanation of the different theoretical methods employed herein, please refer to 

previous works.6,7

This technical note will detail theoretical predictions of heat of formation, density, 

sensitivity and performance for the 1,7-dinitro-3,4,5,8-tetra N-oxide 

bis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (1), 1,7-dinitro-3,5,8-tri N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (2), 1,7-dinitro-3,5-bis N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (3), 1,7-dinitro-1,7-

dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-e]pyrazine (4).8

2. Results and Discussion

The properties of 1, 2, 3, 4 (Fig. 1a–d) were predicted using the ARL tools.7 For 

the estimation of the impact sensitivities, the electrostatic maps on the 0.001 

isosurfaces were generated with the scalar range of the electrostatic surface 

potential (ESP) ranging from –0.05 to 0.075. Recall that for this visualization 

methodology, regions of large positive charge (i.e., electron deficient regions, 

labeled as red) over the backbone of the structure tend to indicate increased 

sensitivity. 
Approved for public release; distribution is unlimited.

2

Fig. 1 Optimized structure of a) 1, b) 2, c) 3, d) 4

The computed heats of formation and crystalline densities for these molecules are 

presented in Table 1.

Table 1 Computed heats of formation and crystalline densities for the molecules

Molecule

Solid phase heat

of formation 

(kcal/mol)

Density 

(g/cm3)

1 230.199 2.038

2 215.463 1.997

3 204.528 1.970

4 207.026 1.885

Additionally, we plot the ESP maps for 1 (Fig. 2a–b), 2 (Fig. 3a–b), 3 (Fig. 4a–b), 

and 4 (Fig. 5a–b) with and without the molecule overlaid on the ESP. When the 

images are analyzed, we would quantify the molecules as sensitive for all 

molecules, with the possible exception of molecule 4, which could be slightly less 

sensitive than the others. We performed Cheetah 7.0 calculations9 to predict the 

performance parameters using the predicted heats of formation and densities. At 

the Chapman-Jouguet point, Cheetah yields the values shown in Table 2.

 

 
Approved for public release; distribution is unlimited.

3

Fig. 2 Electrostatic potential map of 1, without a) and with b) molecule overlay

Fig. 3 Electrostatic potential map of 2, without a) and with b) molecule overlay

a) b)

a) b)
Approved for public release; distribution is unlimited.

4

Fig. 4 Electrostatic potential map of 3, without a) and with b) molecule overlay

Fig. 5 Electrostatic potential map of 4, without a) and with b) molecule overlay

Table 2 Cheetah predicted properties for 1, 2, 3, and 4

Molecule Pressure

(GPa)

Shock 

velocity

(km/s)

Temperature

(K)

Total 

energy of 

detonation 

(TNT eqv)

(per g/cm3)

Total 

energy of 

detonation 

(TNT eqv)

(per g)

1 59.148 10.278 5288.9 2.358 1.914

2 53.617 10.118 5065.5 2.107 1.745

3 48.710 9.973 4751.5 1.870 1.570

4 38.298 9.424 4142.3 1.534 1.346

Note: TNT = trinitrotoluene

a) b)

a) b)
Approved for public release; distribution is unlimited.

5

3. Conclusions

The ARL-developed software tools were used to predict the heats of formation 

and crystalline densities of the 1,7-dinitro-3,4,5,8-tetra N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (1), 1,7-dinitro-3,5,8-tri N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (2), 1,7-dinitro-3,5-bis N-oxidebis([1,2,3]triazolo)[4,5-b:5',4'-e]pyrazine (3), 1,7-dinitro-1,7-

dihydrobis([1,2,3]triazolo)[4,5-b:4',5'-e]pyrazine (4) molecules. 

Using this predicted data, we then ran Cheetah calculations to predict the 

performance of these materials. Additionally, we predicted the qualitative impact 

sensitivities of these compounds using electrostatic potential maps. This 

information has been transitioned back to the requesting synthetic chemist, Dr 

Joseph Mannion of Naval Surface Warfare Center – Indian Head.
Approved for public release; distribution is unlimited.

6

4. References

1. Byrd EFC, Rice BM. Improved prediction of heats of formation of energetic 

materials using quantum mechanical calculations. J Phys Chem A. 

2006;110(3):1005–1013; ibid 2009;113:5813.

2. Byrd EFC, Rice BM. A comparison of methods to predict solid phase heats of 

formation of molecular energetic salts. J Phys Chem A. 2009;113(1):345–352.

3. Rice BM, Hare JJ, Byrd EFC. Accurate predictions of crystal densities using 

quantum mechanical molecular volumes. J Phys Chem A. 

2007;111(42):10874–10879.

4. Rice BM, Byrd EFC. Evaluation of electrostatic descriptors for predicting 

crystalline density. J Comp Chem. 2013;34(25):2146–2151.

5. Rice BM, Hare JJ. A quantum mechanical investigation of the relation between 

impact sensitivity and the charge distribution in energetic molecules. J Phys 

Chem A. 2002;106(9):1770–1783.

6. Byrd EFC. Theoretical prediction of the heat of formation, density and relative 

sensitivity for 3,7-dinitro-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine. 

Aberdeen Proving Ground (MD): Army Research Laboratory (US); 2015 Apr. 

Report No: ARL-TN-0680.

7. Byrd EFC. On the failure of correlating partitioned electrostatic surface 

potentials using Bader’s atoms-in-molecules theory to impact sensitivities. 

Aberdeen Proving Ground (MD): Army Research Laboratory (US); 2013 Sep. 

Report No: ARL-TR-6206.

8. Mannion J. Naval Surface Warfare Center, Indian Head, MD. Private 

communications, 2014 Nov.

9. Bastea S, Fried LE, Glaeseman KR, Howard WM, Kuo IFW, Souers PC,

Vitello PA. Cheetah 7.0 thermochemical code. Livermore (CA): Energetic 

Materials Center: Lawrence Livermore National Laboratory; 2012.
Approved for public release; distribution is unlimited.

7

List of Symbols, Abbreviations, and Acronyms

ARL US Army Research Laboratory

g/cm3 grams per cubic centimeter

DOD Department of Defense

DSRC DOD Supercomputing Resource Center

ESP electrostatic surface potential

kcal/mol kilocalories per mole (unit of energy)

TNT trinitrotoluene
Approved for public release; distribution is unlimited.

8

1 DEFENSE TECHNICAL

(PDF) INFORMATION CTR

DTIC OCA

2 DIRECTOR

(PDF) US ARMY RESEARCH LAB

RDRL CIO L

IMAL HRA MAIL & RECORDS

MGMT

1 GOVT PRINTG OFC

(PDF) A MALHOTRA

1 NAVAL RSRCH LAB

(PDF) TECH LIB

1 US ARMY ARDEC

(PDF) A DISTASIO

1 US ARMY ARDEC

(PDF) S NICOLICH

1 NAVAL SURF WARFARE

(PDF) CNTR 

J MANNION

17 DIR USARL

(PDF) RDRL WM

B FORCH

J ZABINSKI

RDRL WML

M ZOLTOSKI

RDRL WML A

W OBERLE

RDRL WML B

N TRIVEDI

J MORRIS

B RICE

E BYRD

RDRL WML C

S AUBERT

J SABATINI

J BANNING

RDRL WML D

R BEYER

RDRL WML E

P WEINACHT

RDRL WML G

W DRYSDALE

RDRL WML H

J NEWILL

RDRL WMP

D LYON

RDRL WMP G

R EHLERS