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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: ironhorse777 on April 08, 2014, 12:03:28 AM

Title: Directions in Cubic Unit Cell.
Post by: ironhorse777 on April 08, 2014, 12:03:28 AM

Hi, I was just reading about Directions in Cubic Unit Cells and I have a question related to that. Please refer to the drawings 1 and 2  below. The direction indices given are  [-1 1 0]. we move the origin so that the x-coordinate (vector) can come inside the cube. After this for the y-coordinate shouldn't the direction vector be as it is in the figure 2 rather than 1? As y=1 shouldn't we move towards the right of the origin as per figure 2?
Cheers!
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Title: Re: Directions in Cubic Unit Cell.
Post by: Borek on April 08, 2014, 02:51:35 AM

I am not sure what you mean, but if you change the value of any coordinate, you change the direction of the vector.

Title: Re: Directions in Cubic Unit Cell.
Post by: ironhorse777 on April 08, 2014, 03:16:02 AM

Quote from: Borek on April 08, 2014, 02:51:35 AM

I am not sure what you mean, but if you change the value of any coordinate, you change the direction of the vector.

My question was for direction indices [-1 1 0], which drawing is correct? I am just confused how in the book they have shown it like the one in drawing 1 and I am just wondering why cannot it be like the one in 2.

Title: Re: Directions in Cubic Unit Cell.
Post by: ironhorse777 on April 08, 2014, 03:26:47 AM

Sorry really dumb question. Got the answer.