Chapter 139 What is this?
"No, Xu You, isn't your main field physics? When did you start studying algorithms? Besides, material simulation is very difficult to fully simulate. You can't just write a few programs and get any results."
"Professor Xu, in addition to physics, mathematics, computer science and other subjects are also my major subjects. Anyway, let me try it first."
"Okay, the data is in my computer, just go and check it out. The password is your mother's birthday."
"Okay, I understand."
Xu You didn't know what his current computer skills were.
But at least, Xu You could easily solve the undergraduate graduation project in computer science.
Xu You feels that if he masters the basics of materials science and informatics, and can link materials and models well together.
There is still hope to solve the problem of material structure through simulation.
Xu You successfully cracked the password of Xu Zhou's computer and found the relevant data files.
Through the various information in Xu Zhou's computer, Xu You learned about Xu You's methods and data in the preparation of metal atomic clusters.
Although the preparation of aluminum and iron atomic clusters was generally smooth, there were still some atomic clusters with certain atomic numbers that could not be successfully prepared.
As for other metal atom clusters, there is absolutely no idea how to prepare them.
This shows that simply having the same structural model is completely insufficient.
"To obtain the most stable structure of an atomic cluster, the potential energy of the atomic cluster must be at its lowest."
Soon, Xu You found the key.
When the potential energy of an atomic cluster is relatively high, the overall structure appears unstable and the atomic cluster can be easily destroyed.
Finding the relationship between potential energy and spatial structure becomes the key to the problem.
“It seems like this is a math problem.”
There are many factors that affect the potential energy of atomic clusters, and the specific way each factor affects them is also different.
It is not an easy task to construct an accurate function that can characterize the relationship between the spatial structure of an atomic cluster and its potential energy.
"Let's list a few influencing factors first." Xu You thought.
First of all, the most important factor is the number of atoms.
In general, the more atoms there are, the greater the potential energy of the atomic cluster.
This is also why, when the number of atomic clusters is large enough, atomic cluster materials are very difficult to prepare.
The second factor is the structure of the atomic cluster.
Xu You describes the structure of atomic clusters by representing the three-dimensional spatial coordinates of each atom in the cluster.
In addition to these, Xu You also listed other minor influencing factors.
Using the data in Xu Zhou's computer, Xu You adjusted and corrected the function parameters.
When Xu Zhou was free, he saw Xu You's serious look and couldn't help but praise Xu You in his heart.
"As expected of my son Xu Zhou, he is not only extremely talented, but also very serious in his study. It's a pity that the time is a bit short, otherwise he might have achieved some results."
At this time, Xu Zhou naturally would not have any expectations of Xu You, and only regarded Xu You as an intern undergraduate student.
After filling up page after page of draft paper, Xu You finally got a satisfactory functional relationship.
"In this way, the potential energy of the atomic cluster can be expressed."
Xu You has verified the previous data many times to ensure that the result obtained by this function formula has a very small error with the actual value.
This function formula also explains why atomic clusters with a certain number of atoms are difficult to prepare through the same structure.
After completing the design of the function formula, Xu You took the formula to find Xu Zhou.
"Hmm? What is this?"
Looking at the formula on Xu You's paper, Xu Zhou was a little confused.
In fact, the subject of materials is closely related to mathematics, physics, and chemistry.
Many mathematical formulas are also used in daily scientific research.
But Xu Zhou had never seen such a formula before.
"Professor Xu, this is the influence formula of the potential energy of metal atom clusters. Here, E represents the potential energy of interaction between atoms, N represents the number of atoms, ε represents the potential energy well depth of the dimer, σ represents the core distance of the dimer, and rij is the Euclidean distance between any two atoms i and j in the atomic cluster."
Xu You explained to Xu Zhou the meaning of each physical quantity in the formula.
"Although I don't understand how this function is constructed, it does look like that," said Xu Zhouxin.
Xu Zhou knew clearly that these physical quantities were indeed factors that affected potential energy.
The formula constructed by Xu You also feels like the standard formula in textbooks.
Even though Xu Zhou was not sure whether the formula was correct or not, he really wanted to verify it.
"Then let's pick out some data to verify it." Xu Zhou said.
"No need, Professor Xu, I have already verified it. At least the current data is correct."
Hearing this, Xu Zhou was a little bit unbelieving.
"Have you really tried everything?"
"If you don't believe me, try it again."
Xu Zhou did not waste any time and immediately substituted some of his own data for verification.
And when you see these results one by one.
Xu Zhou also had to admit that the result obtained by calculating using this formula was indeed correct.
Even if some individual data have very small errors, they are still completely within the allowable range.
"Sure, son ! How on earth did you come up with a formula like that?"
"Professor Xu, in the laboratory, we should try our best to address each other as teacher and student."
"That's true. Then, Xu You, tell me your thoughts."
Xu Zhou also understood that in such an atmosphere, it would be better to ignore the identities of father and son as much as possible.
Afterwards, Xu You told Xu Zhou about some of his ideas.
Xu Zhou could naturally understand most of it, but wanting to independently create such a function formula was far from being as simple as just understanding it.
"No wonder some aluminum and iron clusters cannot be made. According to this function formula, clusters with these few atoms will show abnormal potential energy."
Although overall, the more atoms there are, the greater the potential energy.
But this rule is not absolute.
After solving the problem of function formula, the next problem is still tricky.
Even if you know when the potential energy is large and when it is small.
However, the minimum potential energy cannot be determined through simple calculations.
There are too many influencing factors here.
Xu You also needs to construct a suitable algorithm to calculate the minimum potential energy structure corresponding to each number of atoms.
