Writing Exercise

Beauty, Form and Function:
An Exploration of Symmetry
Writing Exercise – Hydrogen Bond Phase Transition
(TRACK 2 ONLY)
Writing & Marking Rubric
Instructions:
1.Go to Core Study Resources → III Symmetry in Crystals → Downloads and Links.
2.Download the following:
a. Yoshida et al., Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton
Conductor. Symmetry 4, 507 – 516 (2012).
b. Writing and Marking Rubric

Scaled to 22 Marks

Beauty, Form and Function: An Exploration of Symmetry

Writing Exercise

1. Read Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton Conductor by Yoshida et al
(Symmetry 4, 507 - 516, 2012).
2. Study the Writing & Marking Rubric and prepare an essay of 900 - 1200 words to demonstrate your understanding of the paper. Include descriptions of the:



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Symmetry relationships between the Cs3H(SeO4)2 polymorphs
Nature of hydrogen bonding generally
Driver for the change of symmetry
Linkage between symmetry and proton conduction efficiency

3. Your essay should consist of three (3) and only three paragraphs.
4. No images or tables are allowed.
5. Essay should be prepared in MS Word or similar, and uploaded to Coursera as a pdf.
DO NOT PLAGARISE AS THIS WILL LEAD TO A ZERO SCORE

Beauty, Form and Function: An Exploration of Symmetry
KEY ASPECTS
Paragraph 1 (300 - 400 words)
Compare and contrast the structures the
Phase I, Phase II and Phase III polymorphs.

Paragraph 2 (300 - 400 words)
Elucidate the nature of domain structure in the polymorphs.

Paragraph 3 (300 - 400 words)
Consider the impact of polymorphism on proton conduction.

Note: o Insert Mark at X o A total of 18 marks

Writing Exercise

BEGINNING
1-2 MARKS

ACCOMPLISHED
3-4 MARKS

EXEMPLARY
5-6 MARKS

SCORE

Recognizes the lattice symmetry of the three polymorphs. Describes the evolution of hydrogen bonding for the three polymorphs.

Explains the origin of the change in symmetry with temperature. X

Identifies the features of polymorphic domains seen by optical microscopy.

Describes the mechanism of domain formation. Describes and explains the relationship between the polymorphs that lead to domains.

X

Recognizes the evidence for the correlation between polymorph type and proton transport efficiency. Describes crystallographic models for rationalizing proton transport efficiency.

Describes and explains the mechanisms of proton transport in the polymorphs and implication on fuel cell material selection.

X

Total

X

Links: Conductor. Symmetry 4, 507 – 516 (2012). 1. Read Flexibility of Hydrogen Bond and Lowering of Symmetry in Proton Conductor by Yoshida et al (Symmetry 4, 507 - 516, 2012).